Kewaneh & Shark

The positional differences between NAD83 and WGS84 average less than a meter across the continent. For surveyors, using survey-grade, sub centimeter, GPS systems, it is a substantial difference that must be accounted for. For recreational GPSr users whose GPSr units have a ten meter accuracy (approximately five meters with WAAS enabled) a one meter difference in datum is relatively irrelevant. A GPSr set to NAD83 will still get you to within arm's reach of a cache whose coordinates were established in the WGS84 datum. The differences between NAD27 & NAD83/WGS84 datums are however very substantial, and a GPSr set to NAD27 could be quite a distance from a NAD83/WGS84 coordinate. - Kewaneh

I would agree with CallawayMT. I thought 'Angle Point' when I first saw 'AP'. Do you have coordinates of the mark? It would help us view it on a map and help figure out what it is. - Kewaneh

There are many parts of the country that have, in years past, had a prominent surveyor in the area when that area was developing and growing. The surveyor may have been the County Surveyor, a surveyor appointed by the State or regional government, or a private surveyor who worked extensively in marking the boundaries of private land holdings, public lands (PLSS), and government jurisdictions. When the country was developing, the standards used to identify a surveyed point or boundary corner or line were few and far between. There were (and are) standards for corner identification when surveying the Public Lands (such as cairns, marked rocks, and pits & mounds), but those standards were not always applicable on more local levels for smaller surveys. Surveyors were often left to their own ingenuity for corner identification, and often they settled for a small pile of rocks or wooden stake. Obviously, marks of this type, while they served their purpose in the moment, did little for future retracement as they were often moved, misidentified, or otherwise destroyed. Some surveyors opted for a more permanent solution for the task, either by design or luck. They used well marked stone columns, capped cast iron pipes & pins, or other objects that have weathered the test of time. These designs were often used exclusively by one surveyor and often become known simply as a monument named after they surveyor. In my area, we have such a surveyor and he had such a monument; his marks are known in the area as McKay monuments. Scott McKay was the County Surveyor in the first part of the 20th century. He did a lot of work for the County in subdivisions and resurveys of the Public Lands. He commonly marked PLSS corners and other large surveys with 4" iron pipes topped with a cast iron cap. The cap usually had a square nut in the center and often had 'Fresno County Surveyor' or his name in large raised letters on it. Link to BIG PIC This does not explain what a Thompson Boundary Monument looks like, but it may explain how it got it's name. The term would have been used in the description with the assumption that local surveyors, who knew what a Thompson Boundary Monument is (not recreational benchmark hunters), would be the ones reading the description to look for the mark. Be sure to post pics when you find it. - Kewaneh

I have a RAM Mount holding my Magellan onto the bars of my BMW R100GS dual sport. It's given me many miles of service without any problems. In many cases, RAM Mounts are a bit less expensive than the OEM mounts too. More info can be found in these threads: Motorcycle mounting 60csx Automobile Ram Mount For 60cs 60c Windshield / Handlebar Mount, Get a grip... Hope this helps - Kewaneh

Where is this right of way marker? I'll be in the Central Valley in June and would like to see if for myself! cjf It is located at approximately 36° 32.69'N, 119° 30.20'W (NAD83/WGS84), on Cole Avenue/Road 32 just south of Mountain View Avenue/Avenue 416 (Fresno County Names their roads; Tulare County numbers them.) If memory serves, there is another similar county line monument located at approximately 36° 33.36'N, 119° 29.39'W (NAD83/WGS84). These are both easy to find. They are about 6"-8" thick, 40" high, and adjacent to the road. - Kewaneh

It looks like a right-of-way marker to me. 'R/W' is a fairly standard abbreviation. There was a period of time (the 30's & 40's I think) where the State of California identified their right-of-ways with similar, but shorter, concrete columns stamped with a 'C'. If you could read the 'C', you were in the right-of-way. I've also seen County line markers that look very similar. This is one on the line between Fresno and Tulare Counties in California. Tulare County side (looking into Fresno County) Fresno County side (looking into Tulare County) - Kewaneh

Exactly. Odd as it might be to suggest that a new mark be set because the old mark is being eroded; it's even odder, it seems to me, to say you DID set a mark, but then not say WHERE it is. What's the point? Of course, the information could have been in the hard copy record that never got entered in the NGS datasheet. Bit of a mystery here. -ArtMan- And that is the point I was making. I do think that there was another mark set at the location of MZ0452. I would also agree that there were measurements taken to the new mark but that the data either did not get forwarded to the NGS, or not entered into the NGS bluebooks. My logic lies in the meaning of the word 'set' as used by surveyors, and the clearly stated advisory note found in he description for MZ0453. - Kewaneh

Doing a quick search around your home town of Orrtanna showed these very similar marks: JV1994, JV2034, & JV3387. All identical looking USGS marks mounted vertically on brick churches. Their designations all corresponded with the elevations stamped into them, and one could assume from that that the designation of the mark you found is '608 USGS'. A designation search didn't find a match however. Search coordinates, as the RockHounders mentioned, would definately help narrow down the possibilities. Hope this helps. - Kewaneh

Generally, in surveying notes that state "SET.... ", it is a description of what was set, not an advisory note of what should be done. Most likely, the survey crew was there to use MZ0452, in this case a chiseled square on a concrete base. They saw that the concrete - essentially the benchmark - was being eroded by the water dripping from the tank. They probably set a standard disk in a concrete mound (not 'bound' as described) away from the tower and the water. It is curious that there is no further description of the mark they set. An example of an advisory note can be seen on MZ0453 which states "...A CHISELED HIGH POINT. THIS BENCH-MARK SHOULD BE CHANGED TO A BRASS DISK SET IN ABUTMENT..." Both MZ0452 & MZ0453 were recovered by the NGS on January 1, 1934. It would stand to reason that the same crew recovered both marks. Why they would reset one mark for permanence and then only advise in the notes that another should be reset for a similar reason is puzzling. It could be that MZ0452 was weathering faster than MZ0453. A 'tie' is a reference mark. Multiple reference marks can be used to relocate or reestablish a point, corner, or other survey mark. Other names are 'swing ties' or 'spreaders'. (While the practical use of reference marks, ties, & spreaders is virtually identical, their construction and distances from the marks differ. Reference marks are usually constructed like benchmarks and are placed about 100 feet from the referenced mark. Ties can be chiseled crosses on concrete, spikes or nails and shiners set in power poles or fence posts, or a multitude of other things, and are usually set within 100 feet of the referenced mark. Spreaders are usually nails set within a few feet [1'-5'] of the referenced mark.) TBM is an acronym for Temporary BenchMark. - Kewaneh

From the Ram Mount website, a meridian series cradle is about $10. Probably a couple of bucks for the ball mount. It's the cradle & mount I have on the handlebars of my motorcycle. I've got many, many miles on it with no problems. - Kewaneh

While the marks may have been placed to indicate the location of the quad sheet corner (and its corresponding Lat/Long) I would doubt that the marks are to show two different datums. I could not find any other 'double marks' in the little bit of panning I did on Terraserver. If the two marks were indicative of two different datums, there would be multiple pairs of marks as a datum shift is fairly consistent within any given area. They may be just working marks, left-over from the photogrammetrist who did the photoprocessing. - Kewaneh

There would be nothing wrong with you retrieving it to move it to a cache with more traffic. By leaving it in the cache you did, the TB accomplished its goal of visiting the County, and others had a chance to pick it up. If it hasn't moved, you can move it again. - Kewaneh

It is common in my area (as well as others) to set the Station and RMs in concrete monuments. The concrete monuments are anywhere from 24" to 48" long, and often precast. In order to set a precast monument flush with the ground, a hole with a depth equal to the monument must be excavated first. I would imagine that the intent was to place a concrete monument as the station, and bedrock was found at a depth that did not allow the monument to be placed flush. The crew most likely set the cap in the bedrock knowing that 20" of cover would be excellent protection. Unless you're in a sandy area, you should be able to dig a 20" deep hole that is not much wider that the blade of your shovel, with limited surface damage. If it is sandy, your hole may have to be larger. Just ask nicely and be careful. This is GU1617. It was found in a sandy location, set in a round concrete monument, down about 17". Link to Big Pic - Kewaneh

A better alternative to the ACME crank GPSr is the Analog GPSr offered by AeroStich. Much easier to carry than ACME's GPSr, and mountable to the handlebar of a motorcycle. From their catalog: - Kewaneh

The United States Governement Land Office (GLO), now the Bureau of Land Management (BLM), was given the responsibility of managing the Public Lands. State-wide surveys, for the purposes of land measurement & ownership, were done by the GLO. The survey marks they set were called Section Corners. Additional info about these types of marks can be found in these threads: Cadastral survey disk?, benchmark? BLM Cadastral Survey Marker Cadastral Disks, What is the difference: cadastral, geodetic? Help Me Find What This Is, Pipe cap Us General Land Use Benchmarks Hope this helps - Kewaneh

GU1086 is a brass disk that was mounted vertically onto the base of an airway beacon. The beacon is still standing, although it's no longer in use. While I did get pictures of he disk, I neglected to get any of the tower, but it is there. - Kewaneh

Given only this information for a parcel, it would be imposible to define properly. It does look to be derived from the PLSS system, but that is an assumption. The cardinal quarters shown are not defined as to what they are quarters of: ie a section of land, or a subdivided lot defined elsewhere. The '25-21-9' could be assumed to be PLSS Section/Township/Range, but some areas of the country, and some individual surveyors use Township/Range/Section nomeclature. The whole deed, not only the cryptic property description would be needed to determine the correct intent of the description. Also, the adjoiners deeds, and possibly, a chain-of-title may be necessary to clarify any potential boundary disputes. It should be said here that while research such as this can be generally be done as a private citizen, complete research and the proper intrepretation of intent should be handled by a Professional Land Surveyor. - Kewaneh

I'm not ambitious enough at this point to have a webpage dedicated to benchmark hunting. I do however post my finds online at a photohost site. My NGS benchmark finds are cataloged simply by PID. If it works for the NGS, it can work for me. There's not a lot of description with them at this point, but I'm working on that. It's a work in progress. This page has my galleries of NGS Marks. This page has additional Survey Stuff & Benchmarks. - Kewaneh

Around here, standpipes are no where near as massive as they are in other parts of the country. Standpipes are used primarily (exclusively) for irrigation purposes and are found all over the ag lands. Most are cylindrical concrete, although I have seen a few square ones. They range from 30"-60" in diameter, and between 3'-8' high. A small pump fills the pipe, usually from the top, and the weight of the water carries it through the irrigation pipes to the fields. GU3377 Link to Big Pic GU3381 Link to Big Pic This is an irrigation control structure that works similar to a standpipe. This one has benchmark GU1017 mounted onto the side of it. GU1017 Link to Big Pic Link to Big Pic - Kewaneh

The Adventure Rider website forum has a GPS subforum where GPS tracks are uploaded for everyone to use. The site is used primarily by dual sport riders, but I'm sure that many of the tracked trails can be run with a quad too. There is one recent thread about routes through Moab, Utah. Moab Routes Thread Adventure Rider Website ADVRider Sub-Forum: Layin' down tracks Threads in: GPS Tracks Rockies Hope this helps. - Kewaneh

Here are a few other chiseled marks I've found. Both of these are unique in their own ways. Both are found adjacent to railroads. This is GU0640. It is a chiseled square, but unlike most squares, which are set at the edge of the concrete structure, this one was set in the middle. Link to Big Pic Link to Big Pic This one is GU1061. It is a hybrid chiseled mark - a square with a cross in it. It's the only one I've seen, and I personally don't know that I'd ever set one. I'd prefer them to be seperate marks like on the pump base I posted earlier. Link to Big Pic Link to Big Pic - Kewaneh

Surveyors have been using chiseled crosses as survey marks for many years. They are still used when the situation calls for it, situations where a nail, pin, or other survey mark may not work. Here are some examples: This chiseled cross & square were found on a pump base. Crosses are generally used for horizontal positioning. Squares are generally used for vertical positioning. Link to Big Pic Township 19 South, Range 15 East, Northwest Corner, Section 07. This corner was found about a 0.35 mile hike westerly from the nearest road. Found large boulder scribed with a cross and 'R XIV E' (Range 14 East). (This corner is also known as the SW Cor., Sec 1, T19S, R14E.) This cross was most likely set in the 1880's. Link to Big Pic Township 19 South, Range 14 East, Northwest Corner, Section 12. Found a rock scribed with a cross in the middle of a small pile of stones. Possible remnants of a small cairn. This cross was most likely set in the 1880's. Link to Big Pic Link to Big Pic - Kewaneh

Patty - You don't carry 25 feet of rope in your helicopter? I'd think that anything less than 50 feet would be considered poorly prepared. - Kewaneh

It could also be asked 'Why Geocache'. It seems a little silly for adults to go looking for Tupperware full of McToys for nothing more than a Smilie by your name. What does THAT really count for? Absolutely nothing, ...except that it's fun. There can be a redeeming quality and social significance to benchmarking. If a benchmarker logs his finds on GC.com - or more particularly with the NGS - that benchmarker is helping to further the Geodetic and scientific studies of a particular area. Future surveyors and engineers can read and learn from those logs, and further their work. It is true that the search for benchmarks often teaches a local history. Few caches do that. Whether that local history is good or bad is not as relevant as the possible personal growth obtained by the benchmark hunter. There are parts of the country (and world) where people have done some unconscionable things in the name of race, gender, religion, politics, even safety. There is no doubt about that. But to NOT do an activity simply because it invokes memories of those unconscionable things isn't too intelligent either. George Santayana said, "Those who cannot remember the past are condemned to repeat it." (The Life of Reason, Volume 1, 1905) If benchmarking helps an individual move forward, farther from that history that we may not want to remember, that's a good reason to do it. - Kewaneh

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