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bvrballs

Recovery Advice Needed

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OK, have a couple of new questions. Just spent a weekend at Grand Canyon and did a bunch of benchmarking. Here are my questions.

 

First: The Grandview Fire Tower is a BM described in 1934. It has been reported as recovered on geocaching.com and has also been reported to NGS as recovered by a geocacher in 2005. Problem is, the tower now standing was built in 1936 (told to me by the fire watcher on duty and confirmed on a website discussing known towers in AZ). Even a nearby BM is reported as being 100 feet north of the new tower where the old tower once stood (1958). I know that this isn't really a problem because, since the station described, the old tower, no longer exsists, I should report both as destroyed. Just wanted your opinions.

 

Second: While attempting recovery of a USGS disk described in 1902 with no additional recovery notes, I did locate a USGS disk right where the GPS said it should be. This was out at the end of a point. There are no additional listing in the area by NGS. The problem is that the BM is supposed to have a designation of BISSEL, but the only markings on the disk (besides USGS, elev, etc.) is CANYON. I am having trouble believing that the USGS would have placed more than one BM on this point (about 100 ft wide and only about 20 feet wide at the point where the mark was). I would be happy to report a recovery of the mark and a correction to the 1902 report, but is there somewhere that I can search the USGS to find out for sure that this is the mark I was looking for and not a second mark? Oh, yah. I'll have to update the To Reach since all the original report has is Take the Wagon Rd. Oh, and the location is described as about 7 mi NE of a non-existant hotel.

 

Oh, one more thing. Two of the marks I looked for were not located. Each was last described in 1934. The descriptions were sufficient to make sure that I was in the correct area, but in both cases, it would appear to me that the mark may be buried. One location the mark was described as in a limestone ledge, but the rubble has slid down the hillside and covered the ledge. The other was in a low lying area and was described as being 2" above the ground, but I suspect that the mud and plant matter may also have obscured this one as well. I would suspect that the marks are still there, but I didn't have a metal detector to search. Should I report the no recovery to NGS for these, or just leave well enough alone?

 

Thanks for your help in these matters.

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It is not uncommon for multiple marks to be located near each other, especially at locations that are situated at highly visible locations.

 

It appears that there are quite a few marks set around the canyon marked with the elevation and "CANYON" -- there are at least 19 of them. There are probably many more that never made it into the database. Most of them seem to have been set in the 1930's.

 

I'd say that GP0514 needs to have BISSEL stamped on it, and if you found a mark stamped CANYON, then you probably found one of the many other elevation marks scattered around the area.

 

Also note that BISSEL (GP0514) is a horizontal control point, and wouldn't normally be expected to have an elevation stamped on it.

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Should I report the no recovery to NGS for these, or just leave well enough alone?
I have reported some finds to the NGS. However, since I am not in the surveying profession and don't have professional equipment, I decided long ago to not report my no-finds to the NGS. I leave well enough alone. Perhaps I'm wrong in this decision, but it seems right to me.

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For a FOUND report to NGS the preponderance of the evidence must match the data sheet. If the mark has ADJUSTED horizontal coordinates then it must be within the accuracy of my handheld, whereas SCALED coordinates (most elevation disks) are often off by hundreds of yards. Horizontal control disks usually have reference marks and finding some of them to measure from is strong evidence of what you found. Any description given should be plausible for the date it was written. I have found a few errors on data sheets but only conclude that if the evidence is very strong. Finding a disk with radically different stamping is usually NOT evidence of an error.

 

I make NOT FOUND reports to NGS, when I'm really convinced I've made a good search. The experience of finding dozens of marks helps make the judgment that I've looked hard enough. I learned pretty early that it is easy to fool yourseld so I try to be cautious. A NF without some description of what you saw is pretty useless because it doesn't tell a future searcher whether you drove by and didn't see it or if you spent hours with a tape and metal detector.

 

From what you describe, I would want more evidence than one person telling me the tower was 2 years too new. The description of a nearby benchmark can provide evidence, although I haven't researched the case you mention.

 

If the one on the ledge had good identifiable things to measure from I might report it as "Not found. Rock slide covers location indicated by measurements." If it or the other one were only vaguely described probably would not report them to NGS without a very thorough search.

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I have never reported a "not found" to NGS, for the reasons noted by BDT. There are several, however that I probably will. My criteria for reporting a "not found" would be a thorough search, and a high probability that the mark was destroyed. For example, there are three that I logged NF on geocaching. I am certain they were destroyed, because the rock outcroppings in which they were located were blasted back about another 15-20 feet from the highway's edge during construction. For one of the marks, I also located a reset nearby.

 

However, before reporting them, I am going to go back to the site, make more precise measurements, and do a more careful search for possible reset marks nearby, which would also support the theory they were destroyed. After I do that, I'll report a not found to NGS. I won't if I am reasonably certain the mark is there but I just didn't take the time to make a decent search for it.

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I am also cautious about reporting NOT FOUND to the NGS. If I think the mark is there and that I could find it if I looked harder/longer/smarter than I will not log anything.

 

If I decide I would have little chance of finding it, I will log it with an explanation that would help a future searcher.

 

The worst case is when I log a NOT FOUND and later come back and find it. That's embarrasing to say the least. (I'll bet no one else has ever done that! :D ) I usually explain it to Deb and ask to have the first entry taken out and then add the FIND.

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It is not uncommon for multiple marks to be located near each other, especially at locations that are situated at highly visible locations.

 

It appears that there are quite a few marks set around the canyon marked with the elevation and "CANYON" -- there are at least 19 of them. There are probably many more that never made it into the database. Most of them seem to have been set in the 1930's.

 

I'd say that GP0514 needs to have BISSEL stamped on it, and if you found a mark stamped CANYON, then you probably found one of the many other elevation marks scattered around the area.

 

Also note that BISSEL (GP0514) is a horizontal control point, and wouldn't normally be expected to have an elevation stamped on it.

 

OK, but where do I find the information about these marks? I searched NGS for Canyon in AZ and found only 7 or 8, none of which were in the correct county. Where can I search to find out about USGS marks that are NOT listed with NGS. I may be able to find this one and answer this mystery.

 

Since the original mark, GP0514, was set in 1902, I can certainly imagine that it may be lost due to the rim of the canyon having broken off, and a new disk may have been set. How do I research this?

 

Scott

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From what you describe, I would want more evidence than one person telling me the tower was 2 years too new. The description of a nearby benchmark can provide evidence, although I haven't researched the case you mention.

 

 

Well, as posted originally, the description of the tower being built in 1936 was also confirmed on a seperate website that speciallizes in fire towers for AZ. Also, another benchmark in the area is described in 1920 as being under the tower. It is again described in 1934 as being under the tower. In 1953, it is described as being 100 feet north of the tower and speculates that the tower was torn down and a new one built. In 1956, the mark is again described as being north of the tower and also describes the new tower as having been built in 1936, now a third confirmation of this fact and within the NGS reports. The old tower, which is the mark for FQ0712, has been destroyed. I guess I should have read the other mark's description in greater detail. I now know that I should report the mark as destroyed, which is what I suspected anyway.

 

Scott

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For a FOUND report to NGS the preponderance of the evidence must match the data sheet. If the mark has ADJUSTED horizontal coordinates then it must be within the accuracy of my handheld, whereas SCALED coordinates (most elevation disks) are often off by hundreds of yards. Horizontal control disks usually have reference marks and finding some of them to measure from is strong evidence of what you found. Any description given should be plausible for the date it was written. I have found a few errors on data sheets but only conclude that if the evidence is very strong. Finding a disk with radically different stamping is usually NOT evidence of an error.

 

 

Guess I could have replied to both of these points at the same time, but . . .

 

GP0514 IS listed as ADJUSTED. When I made it to the spot that the unit told me to look, I was standing on this disk. It was about 5 feet or less from the end of the point, and there was no more than about 10' on either side of the narrow point right at the end. For the last 100 yds of the hike, the point was no more than 100' wide. It would seem to make no sense to have a mark here unless it was at the end of the point where it could be used to reference other points along the canyon rim.

 

In other words, it just felt right. Now that's not to say that something might have happened, like the end of the point eroded and this might be a new mark. I'd just like to know where I can research this and, maybe, see the original notes or some further information on this station. The info provided by NGS is very minimal. I suspect that I need to contact USGS for the information I am looking for.

 

Any help would be appreciated.

 

Scott

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Well, as posted originally, the description of the tower being built in 1936 was also confirmed on a seperate website that speciallizes in fire towers for AZ. Also, another benchmark in the area is described in 1920 as being under the tower. It is again described in 1934 as being under the tower. In 1953, it is described as being 100 feet north of the tower and speculates that the tower was torn down and a new one built. In 1956, the mark is again described as being north of the tower and also describes the new tower as having been built in 1936, now a third confirmation of this fact and within the NGS reports. The old tower, which is the mark for FQ0712, has been destroyed. I guess I should have read the other mark's description in greater detail. I now know that I should report the mark as destroyed, which is what I suspected anyway.

 

Scott

 

Not so fast...

 

If I read you right, you are asserting that the tower described in the datasheet is the pre-1936 tower which stood over the triangulation station disk, and the existing tower is not the tower described.

 

In looking at the datasheets for both FQ0712 and FQ0713, both have adjusted coordinates. Running them through the distance/bearing tool I used (which is from the FCC and only accepts 2 decimal places for seconds and gives the distance as .xxx miles) the adjusted coordinates for the tower place it approximately 90 feet away from the adjusted coordinates for the triangulation station disk, at a bearing of 180.00.

 

The datasheet for FQ0713 describes it as approximately 100 feet north of the new tower. I would submit that the tower described is NOT the 1934 tower. With adjusted coordinates, an error of this magnitude is highly unlikely. If it WAS the 1934 tower that was described in the datasheet, the coordinates should be identical (or at least very nearly identical) to the coordinates for triangulation station disk, not 90 feet away. Perhaps the 1934 date on FQ0712 was a data entry error? How did the adjusted coordinates of the tower compare with your GPS?

Edited by andylphoto

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Not so fast...

 

If I read you right, you are asserting that the tower described in the datasheet is the pre-1936 tower which stood over the triangulation station disk, and the existing tower is not the tower described.

 

In looking at the datasheets for both FQ0712 and FQ0713, both have adjusted coordinates. Running them through the distance/bearing tool I used (which is from the FCC and only accepts 2 decimal places for seconds and gives the distance as .xxx miles) the adjusted coordinates for the tower place it approximately 90 feet away from the adjusted coordinates for the triangulation station disk, at a bearing of 180.00.

 

The datasheet for FQ0713 describes it as approximately 100 feet north of the new tower. I would submit that the tower described is NOT the 1934 tower. With adjusted coordinates, an error of this magnitude is highly unlikely. If it WAS the 1934 tower that was described in the datasheet, the coordinates should be identical (or at least very nearly identical) to the coordinates for triangulation station disk, not 90 feet away. Perhaps the 1934 date on FQ0712 was a data entry error? How did the adjusted coordinates of the tower compare with your GPS?

 

My assertion is based on the fact that the tower was observed in 1934, two years prior to the current tower being built. This, in and of itself, would tell me that it was the old tower that was observed, don't you think? I don't think they would have made an error in the date of the first observation since 1934 matches the reporting date of many of the other local BMs, and when they set quite a number of new ones.

 

Scott

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First: The Grandview Fire Tower is a BM described in 1934. It has been reported as recovered on geocaching.com and has also been reported to NGS as recovered by a geocacher in 2005. Problem is, the tower now standing was built in 1936 (told to me by the fire watcher on duty and confirmed on a website discussing known towers in AZ). Even a nearby BM is reported as being 100 feet north of the new tower where the old tower once stood (1958). I know that this isn't really a problem because, since the station described, the old tower, no longer exsists, I should report both as destroyed. Just wanted your opinions.

 

Why report the disk (?) destroyed if it is 100 ft north of the tower? If the tower that has been "Recovered" is at the given coordinates why would you classify it destroyed? The coordinates for the disk are different from the coordinates for the tower. All coordinates are adjusted.

 

Second: While attempting recovery of a USGS disk described in 1902 with no additional recovery notes, I did locate a USGS disk right where the GPS said it should be. This was out at the end of a point. There are no additional listing in the area by NGS. The problem is that the BM is supposed to have a designation of BISSEL, but the only markings on the disk (besides USGS, elev, etc.) is CANYON. I am having trouble believing that the USGS would have placed more than one BM on this point (about 100 ft wide and only about 20 feet wide at the point where the mark was). I would be happy to report a recovery of the mark and a correction to the 1902 report, but is there somewhere that I can search the USGS to find out for sure that this is the mark I was looking for and not a second mark? Oh, yah. I'll have to update the To Reach since all the original report has is Take the Wagon Rd. Oh, and the location is described as about 7 mi NE of a non-existant hotel.

 

When you look at the elevation on the disk "Canyon" it is different from "Bissel" by 4 feet. What was the accuracy of the GPSr when you took the reading for "Canyon"? We know of several locations where there are 2 & 3 disks with-in a 30 foot circle (2 with-in 15 feet of each other!). This deserves a second look. Since one disk was found, maybe enough effort wasn't put into looking for the Station disk.

 

Oh, one more thing. Two of the marks I looked for were not located. Each was last described in 1934. The descriptions were sufficient to make sure that I was in the correct area, but in both cases, it would appear to me that the mark may be buried. One location the mark was described as in a limestone ledge, but the rubble has slid down the hillside and covered the ledge. The other was in a low lying area and was described as being 2" above the ground, but I suspect that the mud and plant matter may also have obscured this one as well. I would suspect that the marks are still there, but I didn't have a metal detector to search. Should I report the no recovery to NGS for these, or just leave well enough alone?

 

Thanks for your help in these matters.

 

Being in the correct "General" area & being in the correct place are not always the same thing! On more than a few occasions we have gone back to find a disk in a spot that "Exactly" matches the description even though it is not where the description took us to the first time around. Only experience will hone your skills to pick up on the important LITTLE hints that are in the descriptions.

 

As to logging with the NGS...Will your log help the next person who goes looking for that mark?

 

John

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Why report the disk (?) destroyed if it is 100 ft north of the tower? If the tower that has been "Recovered" is at the given coordinates why would you classify it destroyed? The coordinates for the disk are different from the coordinates for the tower. All coordinates are adjusted.

 

When you look at the elevation on the disk "Canyon" it is different from "Bissel" by 4 feet. What was the accuracy of the GPSr when you took the reading for "Canyon"? We know of several locations where there are 2 & 3 disks with-in a 30 foot circle (2 with-in 15 feet of each other!). This deserves a second look. Since one disk was found, maybe enough effort wasn't put into looking for the Station disk.

 

Being in the correct "General" area & being in the correct place are not always the same thing! On more than a few occasions we have gone back to find a disk in a spot that "Exactly" matches the description even though it is not where the description took us to the first time around. Only experience will hone your skills to pick up on the important LITTLE hints that are in the descriptions.

 

As to logging with the NGS...Will your log help the next person who goes looking for that mark?

 

John

 

John,

 

Thanks for the comments. Specific answers:

 

The disk which is Grandview was recovered (FQ0713). It will not be reported as destroyed. The question is about the tower (a separate mark). By description, the tower should stand above the mark. The tower (FQ0713) was described in 1934 and has no additional descriptive text. This tells me that the tower described is not the tower that exists. I have been previously told in this forum, and I would quite agree, that the description is the station. With no other information, I can determine that the observed station, the tower seen in 1934, no longer exists. I don't know who submitted the adjusted coordinates, how they were adjusted, etc. I DO KNOW that the 1934 observation of a tower could not possibly be the tower that is currently there.

 

I'm still in a turmoil over the GP0514. The more I learn, the more I don't know what is going on. There was a Bissel point at one time in the Grand Canyon area. I found a few references to it. It is now Comanche Point and is 10 miles from where GP0514 is. This information does not help me solve the puzzle. Is the description for Bissel somehow transposed to the location of Canyon? The elevation I read on the unit was within 6 feet, but since I had not calibrated it within the last few weeks, I have no confidence in that reading. Just earlier this week, it told me that a disk I recovered was -6 feet. I do have some confidence in the location of the disk for GP0514 since I found and marked a road survey mark next to where we had parked the car (about 1/2 a mile from GP0514) and did an average reading to find the estimated accuracy was 7-8 feet. I don't recall the actual accuracy at the time I found the mark, but since I was on a point with nothing around me in almost every direction, I would suspect that it was within 10-12 feet. I did look further to see if I could locate any additional marks in the area at the canyon rim, but did not locate any. Again, since I was at the end of a rather narrow point, I have trouble believing that there were any other marks out there. I found a topo on-line at ASU that shows a BM at the end of the point, but the elevation listed does not match the one stamped on the disk. Maybe it has been adjusted, after all, the original disk was supposed to have been placed in 1902.

 

Anyway, I am not so concerned with proving that I found the mark, I would rather find out the correct information so that I can report correctly. Another geocacher posted to geocaching.com that he found the mark, but I am not willing to do so until I can convince myself that I have, or have not, found the mark. then, and only then, can I report correctly. So my question continues to remain unanswered. Is there anywhere that I can research USGS marks? I doubt that I will ever be able to answer these questions without doing some intensive research. I'm willing to put in the effort, if I can find out where to do it.

 

As for the two un-recovered ones, I think I was in the right area. Yes, more research and searching is required. Following the info provided during the last recoveries put me in the right area. If I had had a metal detector, I am certain that I would have been able to locate one or both of them. I have photos of the features described in the previous reports that I can post to geocaching.com. I think my question was more of a question of if I SHOULD report the no find. I think I'm getting the impression that those in this forum would suggest that, IF I think I have information that may be of use to future searchers, I should probably report it even if I did not find the mark. I guess it all comes down to experience and judgment. I'm 45, so I won't jump to conclusions. I do feel that I should report information if I think it will help. Of the two I was specifically talking about, I an certain I was in the right area because i did the measurements based on the previous reports. One of them, I found what looks like a location where a culvert probably existed (in the right location based on the description and mileage described), but since they have done considerable upgrading to the highway, it was probably removed (checked a half-mile in each direction to make sure there were no other culverts). From that location, I was able to locate a small rock pile in the exact location described (looked like it anyway, and how well can you be sure of a 1934 description? One of the ones I recovered had a 1934 description of being next to a small tree - I took a picture of the large stump and fallen tree trunk that was undoubtedly the "small tree" from 1934.

 

Anyway, I think that I have already, though only benchmarking for a month or so, moved on from the casual search to a more methodical examination before I am willing to say if I found or not a mark, and before I am willing to record that fact, especially to the NGS.

 

Scott

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The disk which is Grandview was recovered (FQ0713). It will not be reported as destroyed. The question is about the tower (a separate mark). By description, the tower should stand above the mark. The tower (FQ0713) was described in 1934 and has no additional descriptive text. This tells me that the tower described is not the tower that exists. I have been previously told in this forum, and I would quite agree, that the description is the station. With no other information, I can determine that the observed station, the tower seen in 1934, no longer exists. I don't know who submitted the adjusted coordinates, how they were adjusted, etc. I DO KNOW that the 1934 observation of a tower could not possibly be the tower that is currently there.

 

Opps. Tower is FQ0712. Observed in 1934 with no additional information. Since the new tower was not built until 1936, can't be the one observered in 1934.

 

Scott

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Opps. Tower is FQ0712. Observed in 1934 with no additional information. Since the new tower was not built until 1936, can't be the one observered in 1934.

 

Scott

 

Your point is taken. However, both FQ0712 and FQ0713 have adjusted coordinates. If the tower described in the datasheet is the 1934 tower, the coordinates would be right on top of each other, not 90 feet apart. You also wondered about who adjusted the coordinates and when.

 

From the FQ013 datasheet:

 

FQ0712.The horizontal coordinates were established by classical geodetic methods

FQ0712.and adjusted by the National Geodetic Survey in August 1993..

 

I agree with your assertion that the 1936 tower couldn't have been observed in 1934. However, consider this. You seem willing to believe that the NGS observed a tower in 1934, adjusted the coordinates, and got them wrong by 90 feet. You note there was a lot of monumenting activity in 1934, with which I will concur. Isn't it also possible that the tower was first observed in 1936 and that someone inputting dozens of 1934 marks into a computerized database made a simple typo, and put 1934 instead of 1936? For me, that seems easier to believe than a 90-foot error in adjusted coordinates.

 

You didn't answer my question before about how the published coordinates of the tower checked out with your GPS. If, in fact, the coordinates match those of the *existing* tower, then it would seem more likely to me that the first observed date is in error. Given the distance and bearing from FQ0713 and the descriptions in the datasheet for that mark, this would seem plausible.

 

Errors in datasheets are not unheard of. For example...I recently contacted the NGS about an obvious error in the elevation of a Michigan mark. It is obviously an error, because it lists the elevation of this mark at about 2,500 feet. The highest point in Michigan is 19xx, so obviously the elevation is in error. The likely error is that the elevation in feet was entered into the database as the elevation in meters. There is evidence that points to this, but it's not provable. See my thread over in the benchmarking forum on this mark, NF0706.

 

I would have no problem contacting Deb and getting this station destroyed if the coordinates put the tower at the location of the 1934 tower. However, that is obviously not the case. It seems to me there is an error in the datasheet. But can you say with certainty that the tower described is NOT the existing one, and that the 1934 date was not a data entry error?

 

If it were me, I think I would visit the site again, and check the coordinates of the existing tower with the published coordinates of the station. If the coordinates seem to be correct for the existing tower, you might contact the NGS about the date discrepancy. Since you noted it, others might too. There may be original documentation they can check to confirm the "first observed" date. I would much prefer to go this route than to try to get the station destroyed, when it may in fact be the correct tower.

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Opps. Tower is FQ0712. Observed in 1934 with no additional information. Since the new tower was not built until 1936, can't be the one observered in 1934.

 

Scott

 

Since the tower has adjusted coordinates, you have 2 choices.

 

1st, the tower was first observed in 1934 and the info you were provided by others is in error. Perhaps the tower was built in 1934 and not put into use until 1936.

 

2nd, the tower was built later and someone at the NGS made an error on the datasheet as to when the tower was first observed.

 

The hard decision is, does it matter when the tower was first observed if the adjusted coordinates match where the tower stands.

 

Intersection stations are very rarely used any more. I believed one of the surveyors who reads this forum said that intersection stations haven't been actively used in over 25 years. If the coordinates match the tower it seems to be a moot point on when it was 1st observed.

 

For the 2 not found disks, Hwy 64 has been rerouted in quite a few areas. Some areas the old highway can been recognized and in some places it is next to impossible to be sure of where the old road went.

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[since the tower has adjusted coordinates, you have 2 choices.

 

1st, the tower was first observed in 1934 and the info you were provided by others is in error. Perhaps the tower was built in 1934 and not put into use until 1936.

 

2nd, the tower was built later and someone at the NGS made an error on the datasheet as to when the tower was first observed.

 

The hard decision is, does it matter when the tower was first observed if the adjusted coordinates match where the tower stands.

 

Intersection stations are very rarely used any more. I believed one of the surveyors who reads this forum said that intersection stations haven't been actively used in over 25 years. If the coordinates match the tower it seems to be a moot point on when it was 1st observed.

 

For the 2 not found disks, Hwy 64 has been rerouted in quite a few areas. Some areas the old highway can been recognized and in some places it is next to impossible to be sure of where the old road went.

 

Sorry, the more I read about this, the less I can buy anything I have seen posted here. The original mark, FQ0712, is a tower observered in 1934. The station mark Grandview, FQ0713, was first described at the base of the tower in 1920. It was recovered in 1934 at the same time the tower was recovered (I would assume the same expidition, but feel free to disagree, though your disagreement would mean nothing). I place no faith in your adjusted coordinates (OK, not yours, but someone's) because I don't know how the '93 adjustment. Obviously they did not re-survey, so I don't know what they did. You put a lot of faith in what is in the datasheets. but then you also are willing to abandon what is there.

 

So, the question is, should I try to follow what is there or follow what is in the real world? What part of the datasheet should I consider golden and what part should I disregard because it doesn't fit my observation?

 

Here is my problem. I have consulted this forum on a couple of issues, and so far, the answers have been ansers of convinience. The datasheet is golden, or maybe they made a mistake.

 

In this case, since ALL the other recovery reports in 50 miles happened in 1934, I choose to accept that this one did too and that they did not make a special trip in 1936 just to see this tower. Everything else about this mark would seem to be moot, including the fact that NGS recovered the Grandview station mark a number of times and failed to pay any attention to the tower since 1934. the tower is gone. FQ0712 is gone and needs to be reported as such.

 

Scott

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Here is my problem. I have consulted this forum on a couple of issues, and so far, the answers have been ansers of convinience. The datasheet is golden, or maybe they made a mistake.

 

In this case, since ALL the other recovery reports in 50 miles happened in 1934, I choose to accept that this one did too and that they did not make a special trip in 1936 just to see this tower. Everything else about this mark would seem to be moot, including the fact that NGS recovered the Grandview station mark a number of times and failed to pay any attention to the tower since 1934. the tower is gone. FQ0712 is gone and needs to be reported as such.

 

Scott

 

What I see is a Datasheet for a Lookout Tower. The coordinates are adjusted (by the NGS, not us or GC.). That means if your GPSr takes you to that tower it is the one referenced in the datasheet. Was it built in 1934 or 1936? I would tend to trust the NGS on when it was 1st observed, but it is possible that a typographical error was made and the date for 1st observation should have been 1936. Do you have proof that it wasn't a typo?

 

Regardless of which is the case, you came to this forum and asked a question, when you had already decided what the absolute facts were. So which part of the datasheet is correct, the description or the adjusted coordinates? I trust adjusted coordinates enough to hunt for drillholes made in the desert in the late 1890's. Whether you trust them or not is strictly up to you.

 

John

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First: The Grandview Fire Tower is a BM described in 1934. It has been reported as recovered on geocaching.com and has also been reported to NGS as recovered by a geocacher in 2005. Problem is, the tower now standing was built in 1936 (told to me by the fire watcher on duty and confirmed on a website discussing known towers in AZ). Even a nearby BM is reported as being 100 feet north of the new tower where the old tower once stood (1958). I know that this isn't really a problem because, since the station described, the old tower, no longer exsists, I should report both as destroyed. Just wanted your opinions.

 

Second: While attempting recovery of a USGS disk described in 1902 with no additional recovery notes, I did locate a USGS disk right where the GPS said it should be. This was out at the end of a point. There are no additional listing in the area by NGS. The problem is that the BM is supposed to have a designation of BISSEL, but the only markings on the disk (besides USGS, elev, etc.) is CANYON. I am having trouble believing that the USGS would have placed more than one BM on this point (about 100 ft wide and only about 20 feet wide at the point where the mark was). I would be happy to report a recovery of the mark and a correction to the 1902 report, but is there somewhere that I can search the USGS to find out for sure that this is the mark I was looking for and not a second mark? Oh, yah. I'll have to update the To Reach since all the original report has is Take the Wagon Rd. Oh, and the location is described as about 7 mi NE of a non-existant hotel.

 

First: It appears well documented in the datasheet for FQ0713 that the lookout tower that was present when it was monumented is now gone. It also appears that the change in location for the tower is documented within that datasheet to an extent that it is as certain as possible without visiting the site that the tower that was observed in 1934 is no longer in existence. At the site, a good test to corroborate what seems obvious from the two datasheets would be to take handheld GPSr readings at the site of the Grandview disk and see how well they agree with the published coordinates. Then take a reading at the tower. I would bet that the readings are spot on, within the level of accuracy of the unit, at Grandview.

 

My guess is that the geocacher who reported the tower as found in 2005 did not do that test and reported finding FQ0712 in error.

 

It is my understanding that ADJUSTED figures on the datasheet are as good as surveyed points can be, whether horizontal or vertical. The coordinates were surveyed as well as they could be and the adjustment is to make refinements from later observations and to adjust from the older datum to the current datum. As such, the published coordinates for a location adjusted horizontal control point should be much more accurate than the expected error of any consumer grade GPS receiver. And that is the basis of the final corroborative test proposed above in case anyone had any doubt as to the accuracy of the datasheet.

 

If the tower does not match the adjusted coordinates, then the most current recovery report for FQ0712 cannot be helpful and could cause a problem should anyone decide to use it's position for survey work. It would seem to me, in that case, that a NOT FOUND report, with an explanation of what was found, would be in order. It would take quite a bit of extra documentation in order to have it classified as destroyed, whether that is worth your while is up to you. I did that with a church spire (MG0680) that was being reported as found even though the church had burned in 1941. Here is a link to that PID on Geocaching.

 

SECOND: As for GP0514: "BISSEL" I would second the statement that it would be highly unlikely that a station designated "BISSEL" would be stamped "CANYON." In the Geocaching Log for that station, the geocacher supplied photographs which clearly show the disk and the area a few feet around it. Not having been there, I cannot be certain, but it appears to me in his area photograph there is a piece of the rock in the foreground that may have been chiseled out. Does it appear that way in person?

 

That could have been the location of "BISSEL" and the USGS could have removed it when the other disk was set. This is only a guess and it would require research with USGS to confirm or deny. Since it is a USGS survey point, they would not necessarily have reported to NGS if such work was done.

 

With the observations you have, I would also report BISSEL as "NOT FOUND"

 

I hope this helps.

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Without getting into the specifics of this issue - which have been hashed and rehashed here - I would like to say a word about horizontal control stations, and the adjustment of their locations.

 

When a horizontal control station is surveyed - whether it be an intersection station like the tower, or a triangulation station like "BISSEL" - the location is determined by sighting a number of adjacent stations using theodolites, setting lights that are observed at night, building towers in some cases so as to better see the surrounding stations, etc. etc. The station in question is in turn observed by these same other stations so the observations are one to many, and many to one.

 

Thus these stations are not surveyed in isolation, but in conjunction with all the neighboring stations which in turn have been surveyed with respect to their neighbors, etc. etc. The result is a vast network of interlinked stations, each with distances and angles measured to other stations of the network.

 

The first step after the measurements are made is to solve the trigonometry equations for all the stations in the area simultaneously, and arrive at the best fit of the data to the solutions of the equations (called a "Least Square fit"). In the old days (pre electronic computers) these equations were solved by people called "computers" and often it would take years. For example, the solution to the equations for the triangulation of New York City in 1909 took 3 years of computation and involved 181 stations and 968 triangles. (Today this probably could be done on your PC in several seconds.)

 

The point of this discussion, is that no station exists in isolation. If through a transcription error the direction to a station was off by even 1 minute of arc, the data would be thrown out since there would be no way to fit the equations with a reasonable probability with such an error. In essence, the location of the station is not just determined by anything done at that station, but rather by it's relationship to all the other stations in the network.

 

So what about adjustment? The initial process of triangulation and equation solving is not an adjustment, that's the starting point. Adjustment is a network-wide correction to all the stations in the network due to change of datum, continental drift, refinement of locations of super accurate primary stations, etc. etc. Adjustments are done infrequently, probably no more than once or twice a decade.

 

The bottom line: the location on a data sheet for a horizontal control station is unlike anything else on the datasheet. It is determined by a mathematical process which operates on the whole network and the resulting accuracy is very high (sub centimeter?). Everything else on the data sheet (names, dates, land marks, etc.) might be in error due to very mundane processes: typos, transcription errors, bad data submitted by surveyors, poor quality of crew, etc.

 

This is why various folks here treat an adjusted location for a horizontal control station with a much higher level of respect than just about anything else on a sheet.

 

Hope this makes sense and adds positively to the discussion.

Edited by Papa-Bear-NYC

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A quick check of the coordinates for the disk that was under the old tower shows 35°57.468' & 111°57.293'. Compare this with the coordinates for the Tower which is 35°57.453' & 111°57.280'.

 

The difference between the 2 set of coordinates put the Tower at approximately90 feet south of the disk & 78 feet east of the disk.

 

This is about where the description says it should be -

1/1/1956 by USGS (GOOD)

RECOVERY NOTE BY US GEOLOGICAL SURVEY 1956 RECOVERED IN GOOD CONDITION. NOTE--OLD TOWER OF 1934 HAS BEEN REPLACED BY STEEL TOWER IN 1936 AND IS 108.2 FT SE. OF STATION.

 

New Tower, new PID, and an adjusted set of coordinates, Hmmmmm.

 

John

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Well, here's my take on this, in terms of a timeline.

 

1. A firetower called Grandview Lookout Tower was built sometime before 1934, probably many years before 1934.

 

2. In 1934, the CGS surveys the area (the 61 and 62 series), and monuments Grandview Lookout Tower as an intersection station.

 

3. In 1936, the old (probably partly wooden) Grandview Lookout Tower was torn down, and a modern steel version, also called Grandview Lookout Tower, was built about 100 feet away.

 

4. In 1958, the USGS surveys the area (the JRH series) and monuments the 1936 version of Grandview Lookout Tower as an intersection station with coordinates different from the old version of the Tower but the CGS and/or the USGS fails to change the date "1934" in the 'descriptive text' (insufficient or missing to begin with), probably because of a confusion resulting from 2 slightly differently positioned towers having the same name.

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Its possible the difference was not noted till much later..Those days communications often took months not nano-seconds.

 

As is this one..

 

RK0487'THE STATION WAS ASSUMED TO HAVE BEEN RECOVERED WHEN THE O-PARTY

RK0487'OCCUPIED THIS STATION. THE MARK WHICH WAS OCCUPIED WAS A NAIL

RK0487'LEADED INTO A DRILL HOLE IN SOLID ROCK (ALTHO THE ORIGINAL

RK0487'DESCRIPTION DESCRIBES THE MARK AS A BRASS

RK0487'FRUSTUM LEADED INTO A DRILL HOLE IN SOLID ROCK).

RK0487'WHEN COMPUTATIONS WERE FINISHED ON THE STATION IT WAS DETERMINED

RK0487'THAT THE POINT OCCUPIED DIFFERED FROM THE OLD GEOGRAPHIC POSITION BY

RK0487'42.32 METERS LONGITUDE AND 8.18 METERS LATITUDE. THE OLD STATION

RK0487'BEING NORTH AND EAST OF THE POINT OCCUPIED. WHEN THIS WAS

RK0487'DISCOVERED, A MAN WAS SENT BACK TO THE STATION TO DETERMINE IF THE

RK0487'MARK FOUND WAS A BRASS FRUSTUM OR A NAIL AND TO SEARCH FOR A

RK0487'SIMILAR MARK IN THE VICINITY OF THE LOCATION GIVEN ABOVE. IT WAS

RK0487'DETERMINED THAT THE MARK OCCUPIED WAS NOT BRASS BUT WAS IRON OR STEEL

RK0487'LEADED INTO THE DRILL HOLE. A SEARCH OF THE AREA INDICATED

RK0487'DID NOT REVEAL ANOTHER MARK BUT A HOLE WHICH APPEARED TO BE A DRILL

RK0487'HOLE WAS FOUND IN A BOULDER. WHETHER THIS BOULDER HAD BEEN

RK0487'BEDROCK AND HAD BECOME SEPARATED COULD NOT BE DETERMINED. NO LEAD OR

RK0487'BRASS THAT COULD HAVE BEEN USED IN THE MARK WAS FOUND. TIME DID NOT

RK0487'PERMIT FURTHER INVESTIGATION.

Edited by Z15

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...Running them through the distance/bearing tool I used (which is from the FCC and only accepts 2 decimal places for seconds and gives the distance as .xxx miles) the adjusted coordinates for the tower place it approximately 90 feet away from the adjusted coordinates for the triangulation station disk, at a bearing of 180.00.

 

Okay...let me stand corrected on this calculation. In looking for an online tool, it didn't occur to me to plug the coordinates into Mapsource and do the distance/bearing calculation there. The tool I used was set to use the great circle method for AM radio, the logic of which I don't begin to understand. For whatever reason, it only calculated the north/south portion of the equation.

 

As John correctly pointed out, the adjusted coordinates for the new tower are also to the east of the coordinates for Grandview. The correct bearing and distance would appear to be 110 feet, bearing 146 degrees. The point remains, the adjusted coordinates place the tower about 100 feet away from the grandview disk, which is what the datasheet describes.

Edited by andylphoto

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This from "seventhings" (who cannot access these fora):

 

"Recovery of FQ0712 based on two factors:

 

1. The tower at FQ0712 and the tower referred to at FQ0713 were two different towers (see difference in adjusted coordinates)

 

2. The position of the tower at FQ0712 was confirmed (within the capabilities of a handheld GPS) with several GOTO fixes from positions along at least two-thirds of the arc of a circle around the tower, and at distances ranging from 30 feet to 200 feet. (The GPS GOTO pointed to the center of the tower continuously for about 15 minutes).

 

If FQ0712 is NOT the tower observed (in whatever year), then it is a tower that occupies the same spot as the tower first observed, within a foot or so. In this case, my "FOUND" will stand, although I'm perfectly willing to qualify my post with a "Caution ...... " if it can be demonstarted that this is not the tower observed.

 

BDT's supposition, above, is consistent with my thinking on the subject. I think that the tower that stands at this spot is the tower PID = FQ0712."

 

Regards to all;

six (for seven)

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This from "seventhings" (who cannot access these fora):

 

"Recovery of FQ0712 based on two factors:

 

1. The tower at FQ0712 and the tower referred to at FQ0713 were two different towers (see difference in adjusted coordinates)

 

2. The position of the tower at FQ0712 was confirmed (within the capabilities of a handheld GPS) with several GOTO fixes from positions along at least two-thirds of the arc of a circle around the tower, and at distances ranging from 30 feet to 200 feet. (The GPS GOTO pointed to the center of the tower continuously for about 15 minutes).

 

If FQ0712 is NOT the tower observed (in whatever year), then it is a tower that occupies the same spot as the tower first observed, within a foot or so. In this case, my "FOUND" will stand, although I'm perfectly willing to qualify my post with a "Caution ...... " if it can be demonstarted that this is not the tower observed.

 

BDT's supposition, above, is consistent with my thinking on the subject. I think that the tower that stands at this spot is the tower PID = FQ0712."

 

Regards to all;

six (for seven)

 

OK. Despite what I have been told in this forum previously, it would appear that the conclusion here is that, despite the fact that the tower was not built until two years after the reported observation, since the coordinates now match the tower that is there, it should be considered recovered. The assumption being that there may be an error in the datasheet.

 

However, the adjusted coordinates of a disk that landed me right on top of one can NOT be considered a recovery because it is unlikely that an error would have been made in the datasheet and since the station names don't match (the station name in the datasheet would seem to belong 10 miles away based on location of the same name, but whatever), it is unimportant that the mark found was dead on.

 

I will try one more time, because so far, I have receive no answer to this question. Where can I do research on USGS marks? I may be able to figure the problem out if I can do some research on it. Anyway, is there somewhere that research can be done on USGS marks? A website maybe?

 

Thanks for your help.

 

Scott

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There is no official website for USGS marks, because there is no database of USGS marks, only paper files. From what I've gathered from previous threads on the topic, you can write or call the regional USGS office and request copies of the USGS data sheets by quad. There is a processing fee for the copies. Zhanna has created a database of some USGS marks for certain regions.

 

Edit: see this thread for the location and phone number of the USGS office that handles data sheet requests.

Edited by holograph

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There is no official website for USGS marks, because there is no database of USGS marks, only paper files. From what I've gathered from previous threads on the topic, you can write or call the regional USGS office and request copies of the USGS data sheets by quad. There is a processing fee for the copies. Zhanna has created a database of some USGS marks for certain regions.

 

Edit: see this thread for the location and phone number of the USGS office that handles data sheet requests.

 

Thanks for the info. I was searching the web last night and located a FAQ that provided an e-mail address (actually two, one east and one west). I have sent an inquiry to that address. Don't know if I'll get a reply. In any case, I will have to be happy with a no find until I can satisfy myself of the correct facts.

 

Scott

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OK, I know I've beaten this one to death, but just want to sum up what has been discussed. Two marks I found were both adjusted in term of horizontal placement, about as good as can be, and well within the accuracy of a handheld unit.

 

The tower, FQ0712, despite the obvious fact that the originally observed tower in 1934 was destroyed and replaced in 1936, should be considered recovered because the coordinates match the existing tower. The assumption is that somehow the 1934 party must have made a mistake as to what year it was that they were there, not that the coordinated were changed later to match what existed later, since there were no additional entries to the datasheet (even though we know that additional parties were there because of a 1958 entry to FQ0713).

 

USGS disk GP0514 should not be considered recovered because the disk that resides in the exactly correct spot does not match the description in the datasheet. Obviously no mistake would be made in the datasheet for a benchmark disk like name, but the year of an observation might be incorrect. Also adjusted coordinates are always correct, unless we are talking about a disk. Also, the fact that s reported station name would more appropriately be used 10 miles away is unimportant.

 

One more thing I have learned, basically from experience, is that the USGS probably doesn’t care much about the many disks it has left around the country, at least not enough to respond to my questions.

 

Scott

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Also adjusted coordinates are always correct, unless we are talking about a disk.
Actually it doesn't matter if it's a disk or not.

 

I have seen several pictures with more than one disk. I think there's one in the benchmark gallery right now. There is also an incredible picture (I don't remember the PID) where one disk is mounted in a way that overlaps part of another agency's disk. Maybe someone else here can recall the PID.

 

Yep, it's all very very complicated. Benchmark hunting sometimes requires a lot more thought and research than one might think.

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bvrballs –

 

Your conclusion is correct, but let me suggest a different line of reasoning.

First, adjusted horizontal coordinates are always precise and 99.9 percent of the time, they’re accurate.

Second, errors in the description section of the datasheet are fairly common (my guess, 30 percent). Most of the errors are minor, some are substantive.

 

To conclude that the tower at FQ0712 is NOT FOUND or DESTROYED, you have to know or assume that there once was a tower over the t-station GRANDVIEW and it stood until at least 1934 (that tower was last mentioned in the 1934 recovery of the t-station), another tower was erected about 100 feet southeast and observed in 1934, that second tower was razed and a third tower was erected in 1936 on the exact same spot (as determinable by a handheld GPS) and on the same concrete footings as the second tower.

 

Or, you can assume that the first tower was replaced in 1936 by a tower about 100 feet southeast and the datasheet typist typed “4” instead of “6”.

 

The probability of the first narrative being true is vanishingly small.

 

Disks are different. For most benchmark hunters, the stamping must match that listed or described in the datasheet, period.

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bvrballs –

 

Your conclusion is correct, but let me suggest a different line of reasoning.

First, adjusted horizontal coordinates are always precise and 99.9 percent of the time, they’re accurate.

Second, errors in the description section of the datasheet are fairly common (my guess, 30 percent). Most of the errors are minor, some are substantive.

 

To conclude that the tower at FQ0712 is NOT FOUND or DESTROYED, you have to know or assume that there once was a tower over the t-station GRANDVIEW and it stood until at least 1934 (that tower was last mentioned in the 1934 recovery of the t-station), another tower was erected about 100 feet southeast and observed in 1934, that second tower was razed and a third tower was erected in 1936 on the exact same spot (as determinable by a handheld GPS) and on the same concrete footings as the second tower.

 

Or, you can assume that the first tower was replaced in 1936 by a tower about 100 feet southeast and the datasheet typist typed “4” instead of “6”.

 

The probability of the first narrative being true is vanishingly small.

 

Disks are different. For most benchmark hunters, the stamping must match that listed or described in the datasheet, period.

 

Agreed, your first assertion is unlikely. That the typist types 4 instead of 6 does not fly either. The reasoning for that is that ALL the surrounding marks were recovered/set in 1934. Some were recovered after ot set prior, but 1934 was a big year for NGS in the area. There is not a SINGLE mention of 1936 in any recovery in the area, period. I would beleive that the coordinated were changed after 1936 but not properly documented, thus explaining why they point to the current tower and not the one observed in 1934. I have decided to report the tower as recovered, but added the information about the date that the current tower was constructed thus leaving the reader to draw their own conclusion.

 

As for GP0514, re-reading the datasheet, there is nothing in the description to indicate what is stamped in the benchmark disk. In fact, there is nothing in the datasheet to indicate why the designation of BISSEL is given at all. The name BISSEL would more likely refer to Bissel point, now know as Commanche Point about 10 miles away, rather than this mark on Zuni Point. I have not yet received any contact back from USGS, but will follow up with a phone call next week to try to figure this issue out before I make my report.

 

Overall, I found my trip to the Grand Canyon rewarding and was able to recover 6 (7 if GP0514 is correct) marks, two of which had not been recovered since 1934 (one of which is still there but has been disturbed - FQ0360) and another last recovered in 1958. The latter, FQ0361, had a description about being next to a small pine tree in 1934. I took a picture of the now large stump and fallen log. I was also able to add information that may be helpful to future searchers for two marks not found and report a mark that is likely lost. All-in-all, a good weekend.

 

Scott

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For anyone still following this thread, I finally got a response from the USGS. What they tell me is that I DID recover station BISSEL. The original disk was placed in 1902 with no station name, as was common at the time. It was later that a leveling was done and the stamping of 7284 Canyon was added to the tablet. As far as the USGS is concerned, Zuni Point used to be Bissel Point. As for the reference I found to Comanche Point once being Bissel point, the dangers of the Internet with a single reference. Still unable to find any other reference on Bissel. Anyway, mystery solved! I actually enjoy the research. I've enclosed the reply for your enjoyment.

 

Scott

 

Scott Kanzelmeyer,

 

This is in response to your questions concerning the benchmark that you recovered in the Grand Canyon Area. The benchmark that you recovered is the U.S.G.S. triangulation station "Bissel" set in 1902 by H.L. Baldwin as explained below in the information from U.S. Geological Survey Bulletin 216 as a part of a control network for the Grand Canyon Forest Reserve.

 

As you will note in the original description that a bronze B.M. tablet was set in solid rock with no stamping indicated. This was a normal practice at the time since many times no name was selected for the station designation when the work was being done. If a name was determined or other designation for the mark during the field work the mark was stamped with that information.

 

In about the same time period spirit leveling was being done by John T. Stewart and as a part of his work he established the elevation for the mark on Bissel Point (Zuni Point) and stamped the mark with the designation " 7284 CANYON". The elevation 7284 was the elevation that was in his field book that he had determined for the benchmark at the time he was doing the work.

 

As for the difference between Comanche Point and Zuni Point both being known as Bissel Point I do not have a good explanation. The only reason that the triangulation station "BISSEL" was named such is "Zuni Point" was given to the field personel as also being known as "Bissel Point".

 

Copied from U.S. Geological Survey Bulletin 216, PRIMARY TRIANGULATION AND PRIMARY TRAVERSE, Fiscal Year 1902-03, pages 151 &152.

 

ARIZONA.

TRIANGULATION STATIONS.

 

Mr. H. L. Baldwin, topographer, was engaged in March and April, 1902, in extending triangulation northward from the base New River-Union for the purpose of furnishing control for the survey of the Grand Canyon Forest Reserve.

He, established and marked the position of 18 primary stations which control 7 thirty-minute quadrangles and 5 secondary stations which control the Jerome special quadrangle, observing for azimuth at two stations.

 

BISSEL, COCONINO COUNTY.

 

About 7 miles northeast of Grand View Hotel; reached by wagon road. Lines of sight were cleared - to San Francisco Mountain and Kendrick.

 

Station mark: A bronze B.M. tablet set in solid rock. [Latitude 36 00' 52.00" , Longitude 111 54' 45.20"]

 

Copied from U.S.Geological Survey Bulletin 463, SPIRIT LEVELING IN ARIZONA, 1899-1909, pages 79 & 80.

 

Bright Angel, Shinumo, and Vishnu Quadrangles.

 

 

COCONINO COUNTY.

 

The elvations in the following list are based on an aluminum tablet in rim rock north of Bright Angel Hotel at Grand -Canyon, stamped " 6866 CANYON." The elevation of this bench mark is accepted as 6,861.409 feet, as determined by primary levels along the Grand Canyon Railway, corrected to the unadjusted elevations of bench marks at Williams determined by precise leveling of Coast and Geodetic Survey in 1909. The leveling was done by John T. Stewart in 1902 and 1903, and by M. S. Bright in 1904.

 

BRIGHT ANGEL QUADRANGLE.

 

Grand Canyon southeast along stage road via Grand View Hotel to Zuni Point (Bissell Point).

 

Grand Canyon, station, point on rim of canyon, 100 feet north of )Bright Angel Hotel, in rim ledge; aluminum tablet stamped "6866 CANYON" ---------------------------------- Feet. 6,861.409

 

VISHNU QUADRANGLE.

 

 

Head of Red Canyon or New Hance trail to Bissel Point (Zuni Point),

 

Morans Point, northern point of upper strata of limestone at rim; aluminum tablet stamped

" 7157 CANYON" ----------------------- 7,151.974

Bissell Point (Zuni Point), top of strata of limestone at rim; bronze triangulation tablet stamped

"7284 CANYON" -------------------- 7,279. 387

 

Copied from USGS files for horizontal and vertical control in Arizona:

 

LINE 2.

 

FROM GRAND VIEW NO.2 QUADRANGLE (395) NORTHEAST TO MORAN AND ZUNI POINT (by J. T. Stewart, 1902-1903; Book 9462)

 

Moran Point, 0.2 mi. N. Of jct. Of State Highway 64 and rd. to Moran Point; at rim of canyon; in E. end of limestone ledge; standard aluminum tablet stamped "7157 CANYON" (recovered by USC&GS, 1934,) elevation 7150.530

 

Zuni Point (Bissell Point) in limestone stratum at rim; bronze triangulation tablet stamped "7284 CANYON" elevation 7277.920

 

The benchmark is published on the U.S.G.S. 7 1/2 min topographic map "Cape Royal, AZ" as BM 7278 located on Zuni Point. I hope this helps in you with the history of the benchmark Junipara Henkel/RGIO/USGS/DOItablet that you found at Zuni Point.

 

John

 

John Sellars

US Geologcial Survey, NGTOC II

Bldg 810, MS509

Den Fed Ctr

Lakewood, CO 80225

(303)202-4371

e-mail jrsellars@usgs.gov

 

----- Forwarded by Brenda K Barski/RGIO/CONT/USGS/DOI on 08/23/2006 11:51 AM -----

"Scott W. Kanzelmeyer" <scott@kanzelmeyer.com>

 

08/22/2006 02:45 AM

 

To: infoservices@usgs.gov

cc:

Subject: Questions About Grand Canyon Benchmarks

 

 

USGS,

 

I was recently in the Grand Canyon and recovered a benchmark that now has me

curious. The mark is listed with NGS as PID GP0514 and has a listed designation

of BISSEL. Their datasheet gives adjusted coordinates of 36 00 56.54731(N)111

54 43.62538(W). The mark was described in 1902 by USGS as located about 7 mi NE

of Grand View Hotel (which no longer exists). When I made my way to the end of

Zuni Point, my GPS placed me directly on top of a USGS BM, but the disk was

designated as Canyon and showed an elevation of 7284. My question is this, did

I find the 1902 BM or was a later mark placed on Zuni Point? If this is a

replacement disk, do you have any information as to the fate of the original disk?

 

The thing I find most curious about this issue is that the only reference to

BISSEL I can find near the Grand Canyon is that Comanche point, about 10 miles

NE of Zuni Point, is said to have once been called Bissel Point. It would make

more sense to me that a station named BISSEL would have been located there.

 

Anyway, any information you can shed on this mystery would be greatly appreciated.

 

Thank you for your help in this matter.

Scott W. Kanzelmeyer

 

--

-

********************************************************

Scott W. Kanzelmeyer scott@kanzelmeyer.com

Kanzelmeyer Family Homepage - http://www.kanzelmeyer.com

Personal Homepage - http://scott.kanzelmeyer.com

 

"It is better to have lived vicariously,

then to never have lived at all."

- Scott W. Kanzelmeyer

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For anyone still following this thread, I finally got a response from the USGS. What they tell me is that I DID recover station BISSEL. The original disk was placed in 1902 with no station name, as was common at the time. It was later that a leveling was done and the stamping of 7284 Canyon was added to the tablet. As far as the USGS is concerned, Zuni Point used to be Bissel Point. As for the reference I found to Comanche Point once being Bissel point, the dangers of the Internet with a single reference. Still unable to find any other reference on Bissel. Anyway, mystery solved! I actually enjoy the research. I've enclosed the reply for your enjoyment.

 

Scott

 

 

Hey congratulations. Now you have information to update the NGS data sheet. That info will save the next finder from the confusion you endured. Good piece of detective work.

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