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I have been finding a lot of benchmarks in my area on the USGS TOPO maps.


I have three questions.


(1) I haven't physically found them yet, but is there a way to log them with the NGS, or would they even want that info. (They are not in NGS database.) and if I do log them (when I find them) I'll have to start another post to learn how to do it up to NGS standards.



What are the symbols used for the BM's, like Ive seen both an X and a triangle symbol. Vertical and horizontal control point?



I found one BM on the NGS database, (It's not on the map, placed in 2002) it is a satellite control point. I suppose that is a different post, but can I log it with NGS and how?

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Let me take a wack at this.........


(1) Some of the marks on the TOPO maps will be on the NGS database. Some of the marks are even on the GeoCache database. But not all USGS marks will be on either database. If they are not on the GeoCache database, you can't log them there. If they are not on the NGS database, you can't log them there either.


You have to remember that NGS and USGS are 2 separate things. I once found a NGS marker 6 feet from a USGS marker. Both in good condition. Each have their own database.



The marks on the TOPO map are a "X" for a "standard" benchmark. The little triangle symbol is for a triangulation station benchmark.



How old is the TOPO map you are using? If it's a NGS benchmark, it might not be listed on the TOPO map, especially if it's a fairly new one. If it's not on the database, you can't log it.


-my 2 cents worth

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The USGS maps are the standard from Terraserver, I think they are dated 1954. Is there a database of USGS benchmarks?


I don't really care about logging them if they have no database. I suppose when Waymarking comes I can put them in there, but no big deal.


I'll probably go after a few, take some pics, and just see if I can find them, the fun is mostly in the hunt. I like to log, lets everyone you found it, but it's not everything.

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Airmapper -


Is there a database of USGS benchmarks?

Some of us (not me) have contacted the USGS in various ways about either getting data on marks or giving them recovery logs. It appears generally that:


1) Most or all of their data is on pieces of paper in file cabinets, never to be entered into a computer. I've seen some examples posted here and some of it is handwritten, as I recall.


2) From some USGS locations you can buy copies of these pieces of paper by Topo Quad.


3) I've seen posts here indicating that the USGS is not extremely excited about getting recovery logs from anyone. However, no USGS person has ever come here and posted about getting recovery marks for their disks as far as I know.


Perhaps someone who has contacted them could elaborate further.


Here and here are examples of USGS location data provided by Z15.


Here is the post about buying USGS datasheet ("control") information, also provided by Z15.


Here is a discussion from last month indicating why there is no USGS online database.


It does seem that Z15 is our resident expert on USGS data! B)

Edited by Black Dog Trackers
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I've been on a tour at the Mid-Continent Mapping Center at Rolla, MO (home of the USGS in this region) and they said the same. The USGS benchmark database is on 8.5 x 11 pieces of paper in hundreds of folders in dozens of file cabinets.


They have no current plans to computerize it.


......however, there are SOME USGS benchmarks also included on the NGS database.


If you find USGS marks, the guys who took me and my daughter on the tour said that he had no idea where I would log them at the USGS.


A funny story: The MCMC has a 1-room visitor center / museum and they show a 20 minute video. The guy who gave us a tour said they get about 2 to 4 people a week through there. When I mentioned that I was into recovering benchmarks and mapping in general. he got another guy and they both showed us around the building (apparently even into some areas where visitors usually don't go!). They were so excited that someone who was actually interested was visiting!

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Thanks for the info. Now I think I'll just try to find them, and take a photo. If wayarking comes along and I can enter them fine, if not, also fine.


Several of them are right off the road and I pass them weekly. Now I just have to find them.


One in particular has my interest, simply because I can't find a point on the map to match the description. It is the one I found on the NGS database, it is DG7973. I know the roads around here, but the description doesnt make sense. I want to at least have some coords so I can get within 200 feet or so, I can find it from there. (it is supposed to be in the road right of way.)


What format are the datasheet coords in. I'm thinking DD*MM. MM.M, but that doesn't seem to work.

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Thats what I got, how would you put that into a GPS or mapping format, just simply remove the extra 4 ssss of the back? I tried that, and it gave me an odd position, not far (say only a mile) from where I would expect it to show up. But definately not fitting the description.

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Thanks, I figured out my problem, I had the right coords the whole time. I convinced myself it was somewhere it wasn't. Now I know about where it is and it will probably only take me a couple minutes to find.


I expect I'll probably find some of the other, unidentified BM's, but several could be missing. I noticed that BM's in church yards and cemeteries do well as being where they are supposed to be.

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I'm not quite sure why there is all this interest in marks that are not in the NGS database.


It seems to me that with more than 700,000 eligible marks, and fewer than 10 percent of those logged (see the stats at the top of the Benchmark Hunting page), there are plenty of unfound marks in the database that are worth looking for.


Or maybe people just aren't reading the FAQ?



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I spend about half my benchmarking time, looking for non-pid marks from topo maps.


Most of the time, I use NG Topo with a GPS receiver to track my position. I'll occasionally check out my surrounding area as I'm going (wherever). Usually it's when i'm out on a "sunday drive", looking for PID marks, geocaching, whatever.


I'm having about as much success at finding non-pid marks from a map, as I am from the marks with the datasheet and descriptions (roughly 50% finds). For the ones I find from topos, most all of them are "walk right up to it and see it" recoveries.


As for hints to finding the actual marks: Obviously, having some experience at finding them helps, as it gives you a head start of what you are looking for, and where to find them. Bridge abutments, sides of buildings, sidewalks, culverts, RR signals, typical "round concrete monument", are among the typical spots I've found.


One area near me, does seem to have a fair number of them in the sidewalks / porches of older farmhouses.


The most interesting non-PID mark: In the middle of the front yard of a farm house & barnyard, was a section of concrete like a sidewalk. Embedded in the concrete were 3 gravestones, and a USGS benchmark. After asking the resident about this item, and a long conversation, I found out some interesting facts.


This 400+ farm (in south-central Ohio) was given by Thomas Jefferson to the great-(???)-grandparents of the current landowner around 1804. Several barns, located near the brick farmhouse, are actually "shells" constructed in the 1950's over the original log barns from the 1800s. I got to see the log-barns, made from HUGE timbers.


The markers were those of the original landowners. The bodies were moved to a nearby cemetery, after the remains were discovered. The original markers were set into concrete in the late 1950's, just before the USGS came through and set BMs. One was set into this pad, and had I not been looking over the map for the area for BM, I'd never had learned this interesting tidbit of local history.


Edit: (For some reason my mouse quit working, and I had to reboot before finishing my post).


Reason why I hunt them: Other than the occasional "interesting experience" (as above), I'm running out of PID marks in my immediate area that are "safe" to hunt. I also enjoy the challenge. I"m not after the smiley on GC, or the number of NGS recoveries (though I do log both).


I'm weird... :(

Edited by Crystal Sound
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Great story.


What intrested me about unmarked BM's is the fact I go by them every day. Most of the BM's in my area with PID's are either next to an old RR, or in town. Most of the BM's on the TOPO maps look like they are pretty easy to get to, and I was suprised at how close they were, and how many there was.

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While I generally agree with ArtMan's comment above - "I'm not quite sure why there is all this interest ...." - I am guilty of finding and documenting benchmarks that are not in the Geocaching database. To date, I have recovered and documented 110 non-Geocaching marks. The breakdown is:


17 no-PID Mason-Dixon stones or other pre-1900 stone boundary markers,


21 Lewis & Clark commemorative marks (10 of which have PIDs in the NGS database),


9 marks that have PIDs and are in the NGS database but not in the Geocaching database (all set in 2000 or later), and,


63 disks that are in neither the NGS nor the Geocaching database. These are marks that I just stumbled across while looking for marks with PIDs or no-PID marks of historical interest.


That said, I agree with the ArtMan: there does not seem to be much point in searching for no-PID X's on a toposheet. On the other hand, I see nothing wrong with it either. I do see the point of the kind of systematic work that Wintertime does in Yosemite and in coordination with the USGS (I think Zhanna does similar hunting).



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In answer to ArtMan's query, one facet of the non-PID marks is the BM markings on topo maps. There are many many people (not me, particularly) who just love topo maps! Any serious topo map person will eventually be intrigued by the BM marks, especially when they realize that they are part of how topo maps were made. Gotta find some! Etc.


Imagine, before knowing about the NGS database and before GPS, finding one of those was a much more difficult puzzle and challenge than finding a PID.


Hang onto your non-NGS USGS finds! Waymarking programming IS coming to benchmarking on this site, and USGS markers (and the rest) will be able to be logged then.

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Another aspect of non-PID benchmark hunting is those who work with a state or local geodetic agency to recover their markers. I've been doing some hunting for the City of Albuquerque agency; not very interesting marks because they're all on street corners/curbs/lamppost bases, but there's 2,000 of them within 1/2 hour driving distance. They also have the nipple style markers, which are different than the usual disk.

Edited by BuckBrooke
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Just to clarify my post —


Being fascinated with topo (or any other kind of) maps I understand.

Wanting to search for non-NGS marks I understand.

Photographing or otherwise documenting those marks I understand.

Wanting to report them to the monumenting agency I understand.

Its the urge to log them on Geocaching.com that I find a bit baffling.


Unlike caches, benchmarks on Geocaching were, are, and IMO will always be an afterthought. They are a finite universe. They will almost certainly not be expanded to include newer NGS marks or those of other federal, state or local agencies.


If you have your heart set on logging a benchmark on Geocaching.com, then search for the marks that are eligible for logging, i.e. the NGS marks in the Geocaching.com database.



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I'd like to log marks I find, but if I can't I'm not going to be too disappointed. My thinking is if you have a way to log it, in effect you are sharing the position (or Information) of something of interest. If it's not interesting (or not there) then maybe your giving a heads up that says "don't waste your time on this one." (Or to some of you that's an invitation to come look harder.)


Benchmark hunting has it's differences and similarities to Geocaching. The big differences being what you seek, and what to do when you find it. It would be nice if benchmarking had a site of it's own, but if not for this site, where would you start. I knew nothing of BM hunting until I came here to cache.

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I just found a Benchmark that showed on my USGS Topo. It is listed as BM 5385 and is not in the Geocache.com or NGS's site.. I just wanted to see if it was still out there. So I visited a few sites in order to figure out the coordiantes and got within 15 feet of it.. Now to see if there is any info on the net concerning this Benchmark..

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>where's the info to go with it?


In a file cabinet at the US Geological Survey. Like thousands of other disks they set, used, and may continue to use for mapping purposes, they didn't work up the measurements in the form and to the standards of NGS and submit the data for inclusion in the geodetic data base.

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It sounds like you found the witness posts. The benchmark description usually tells how far and what direction from the witness post to look for the benchmark.

I did think I was missing something, my GPS led me right to the witness posts, but since thier USGS Non-Database marks I coulden't get any info before I was there. Now it gives me an excuse to go back.


I did find an interesting disk on another non DB mark, it did not have the altitude stamped, just an ID mark and a year, 1939 I think. I found several witness posts and the one disk near my camp which I looked up on the USGS Topo maps and set my GPS to find.

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