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NGS "Not Found" for a reason?


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Maybe this has been discussed before, but searching isn't turning up much. In short I'm wondering if anyone knows if NGS had a policy or at least habit of marking certain benchmarks as "Not found" for a reason. I've been looking at several counties around me, especially early benchmarks placed by the railroads in the early 1900's (mostly bolts and rivets), and I've noticed some patterns in the records that lead me to think this may have been done.



1) Most of the benchmarks I'm looking at were placed by railroads, mostly ATSF at unknown dates (probably between 1910-1920 based on depot dates.

2) It appears NGS went around the area in 1933 and 1934, at that time they logged most of these bolts and rivets as "Found" and added their descriptions. During these same years they also placed their own standard discs, all stamped 1933 and 1934 as well.

3) During a few specific years, mostly 1964 and then in 1975 and 1976, NGS marked many of these bolts and rivets as "Not found", or there simply are no more logs after the initial 1933 & 1934 logs. This seems to apply to EVERY bolt and rivet I've read the data sheet for, encompassing several counties and probably 50+ bolts and rivets. Every one is either marked "Not found" in the years I mentioned above, or simply has no log after '33/34.


So my theory is, NGS logged these initially, perhaps using them as a reference for their own discs, and then later marked many of them as "Not found" either so they wouldn't be used, or whatever other reason may exist. I know there are standard discs that were placed by the NGS in 1933 and 1934 have been marked as "Not found" by the NGS, but still are in existence, but I've yet to find a fellow Geocacher's log about finding a bolt or rivet so far. I still have some research and real hunting to do once it gets warmer, but I was seeing if anyone else has noticed a similar pattern or has any other input.

Edited by tdx
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If all of the marks along a rail line are NF, it probably means the RR went through and replaced bridges and culverts so the old marks were destroyed.


If NGS themselves logged a Not Found, it means a trained person made a search and did not find it. Sometimes in the last decade or two they would post USPSQD or other entity reports to the data sheet and unless you look close you might think it was the result of a search by NGS. The other entities were in some cases not as thorough as NGS and their NF is less definitive.


Once in a while someone finds a mark that NGS couldn't. That's a real victory that doesn't happen often. Usually it is because circumstances have changed to make the mark more visible, more modern tools like metal detectors and handheld GPS were not available to the older searchers, or the recent finder knew the local area better and could interpret some historical clue.


The fact that there are no recent logs is not to be taken as any indication the mark is gone. The NGS does not routinely check on them, unless they are doing a project in an area and need to use them. Other users may not take the time (expense) to send in updates.


NGS does not report marks as NF to keep them from being used. They have codes for things like "No Geodetic Data" for cases where it is determined the data was not accurate.


Much of the Coast and Geodetic Survey (now NGS) measurements were done in the 1930's and they sometimes measured previously set railroad marks where they were convenient so they did not have to set their own disks. But CGS would have remeasured them using superhuman precautions to get the best possible accuracy. The RR probably used only reasonable care in their own prior measurements.

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I have found dozens of bolts and rivets here in Arizona, and have also not found many as well. Sometimes it's obvious the bridge, culvert, or signal base have been removed or modified...sometimes not so obvious.


Actually setting the marks is probably the least intensive part of 'making a benchmark'. The measurement process and the 'bluebooking' are VERY precise and time consuming, so it's unlikely the NGS would 'just toss out' any subset of marks 'so they wouldn't be used'.

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It would be difficult to improve on the two excellent answers, above! So I'll just slip in a reminder that marks such as you are describing frequently have SCALED horizonal coordinates--meaning the published coordinates might be off by several hundred feet.


Once you are in the general area, follow the To Reach in the description. Also check the TOPO map for that quadrant. Occasionally, the disk's location is indicated by an "X" and the letters BM, followed by the elevation (which may not match the datasheet elevation exactly).


Marks with ADJUSTED coordinates are very precise. But the To Reach and reference objects still are very useful in helping you dig only one hole. [Grin.]


You mentioned marks along rail lines. Disks along railroads sometimes were set on pipes projecting several inches above ground. Unfortunately, this made them easy targets for the equipment used to maintain tracks and rail beds. When stations still exist, they may be under several inches of gravel.


[As always, we include the disclaimer that railroads take a dim view of people trespassing on their right-of-ways. The rail industry has a very good safety record and wants this to continue in the future. The majority of injuries and deaths are not railroad workers. Instead, it tends to be the public--walking along a track, or in an automobile.]


As Bill93 pointed out, a lack of reports, or even a NF, does not mean the mark is gone. But if it was along a railroad, it may have led a rough life. [Chuckle.]




A lady and her automobile were dragged 500 feet by a train, last week, in Johnston County, NC. She survived. Her explaination for being hit? "I had the music turned up real loud and didn't hear the whistle."

Edited by PFF
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..I've had similar experiences - an old line near me was decommissioned in the 70s that had some disks & a lot of rivets. A number of the rivets were reported as NF by the USE during the 50s.







All were easily found - and I had no trains to worry about! (I wonder if the USE NFs were actually 'not searched fors')


The disks that are smattered here & there along the same RR line appeared to have been ignored by the USE in 1952, even though the disks were set in the 30s. It may be that the recovery parties were only interested in recovering a certain 'string' of marks when traveling thru an area (or only have/had that info w/ them).


So by all means, they could be there. And be mindful of PFF's warning about the trains!

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---- (I wonder if the USE NFs were actually 'not searched fors')----


So by all means, they could be there. And be mindful of PFF's warning about the trains!


About ten percent of my recoveries in the last two months are previous NFs. I agree that there must have been a NsF factor here in the Gallatin Valley; and some times a new mark was monumented nearby rather than an extensive hunt.


QX0244 was FOUND in 1982, but just under one mile east at an obvious siding area of the abandoned rail road there remains to this day a witness post marking QX0243 which was recovered as NOT FOUND then.


QX0254 was apparently put in in 1960 to replace QX0253 which they did not see flush with the ground 60 feet to the north.


I know that it is a bit easier hunting out here in the big open, but the DATASHEET was the only tool required for the above examples.


I take a quick look at at every DATASHEET location that I pass by.


Sun starting to shine - I better go do that. Hoping to pick up a couple of 1907 Precise Level Net NONPIDs in the Livingston, Park County area. MEL

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Thanks for the helpful replies everyone. I continued trudging through datasheets and have found one rivet that is logged as Good by the NGS in the early 80's, and one abutment that has info from a Geocacher as found, though the rivet was not witnessed as it was overgrown, but was identified as being dated 1929, so it is likely still there. I know a benchmark near a railroad can lead a hard life, but most of the ones I'm looking at are located 10-50 feet away from the rails, some even appear by topo map to be located well off the roadbed in private land (description agrees there is considerable distance between the centerline and benchmark), so I'll be tracking down some land owners to see if they'll allow me to search for them. Also the two railroads with lots of bolts and rivets have long since been abandoned and most of the rails removed, this was not done until I believe sometime in the late 80's or early 90's, so many benches logged as NF in the 1960's and mid 70's I'm hoping may still be around.


Ernmark, nice finds there, it's interesting how you have two that appear to be hiding in plain sight, though logged as NF. Although you have a different railroad and agency reporting NF's, the datasheets look similar to the ones I'm interested in, found one day and "NF" years afterwords.


Thanks again for the helpful insight everyone.

Edited by tdx
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NGS uses temp help so if they marked it not found, maybe they just did not look or were so totally unfamiliar with the area they were in essence lost.


Back in 1985 NGS ran levels across the UP of Michigan. Quite a few marks along their route were reported by them as not found. But in my work at the M-DOT we came to find a lot of the marks that they reported as not found. Some were so evident with witness posts and in plain sight that the only conclusion you could come to is that they never really searched for the mark. Or the NGS advisor surmised, they did not want to find it for what ever reason and marked it not found to eliminate it from being tied in by the level party. Rules of the work often required them to look for and tie into all marks within so many KM of the level line. That would mean much more work and much more time. If you are running levels from Marquette Michigan to Duluth, Minnesota they probably had to determine that some marks would be tied and others would not due to time and cost constraints.

Edited by Z15
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Excellent answers above. And in regards specifically to Z15's reference to the U.P. of Michigan, I've also found quite a few that were "not found" by the party in 1985. While some may be legitimate, for many I can only conclude that "not found" really meant "not looked for." A number of these were along an abandoned rail line and required at least a significant drive along a highway abandoned 50 years ago (now a two-rut road) if not a good walk through the woods or along the old grade. I was also helped in my search on a number of these by adjusting coordinates based on topo map info and using the GPS. Most or all references on some of these were to the rail line, and basically useless.


Some examples:













There may be a couple more, but those are the ones I can think of. There are also several that I have not located yet--some I haven't searched for, and some that will require a second trip with more time. Some may be there hiding, but others are likely destroyed.

Edited by andylphoto
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---- conclude that "not found" really meant "not looked for."


Another possibility: "Its goota be good, cause we can't get there!


RW0537 HISTORY - Date Condition Report By















How did this one get a PID? MEL

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