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t8r

USGLO benchmarks

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A friend that works in the area brought me a GLO brass cap the other day (that he found in a gravel road) as he has heard me talking about BM hunting. At first i thought it was a weird cadastral marker. After closer examination, i realized that i have an actual GLO benchmark from 1911. Examination of the topo in the find area reveals many such markers. The one i have is marked for elevation 5601; the map BM at the found location indicates 5600 feet, i suppose an adjustment was made to GLO or BLM data here.

Coordinates as determined from google earth are N41° 50' 23.94" by W116° 14' 04.36".

I wonder if anyone knows of any info on these BMs.

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A friend that works in the area brought me a GLO brass cap the other day (that he found in a gravel road) as he has heard me talking about BM hunting. At first i thought it was a weird cadastral marker. After closer examination, i realized that i have an actual GLO benchmark from 1911. Examination of the topo in the find area reveals many such markers. The one i have is marked for elevation 5601; the map BM at the found location indicates 5600 feet, i suppose an adjustment was made to GLO or BLM data here.

Coordinates as determined from google earth are N41° 50' 23.94" by W116° 14' 04.36".

I wonder if anyone knows of any info on these BMs.

I have a picture but cannot post as i do not have an approved url for it.

Edited by t8r

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A friend that works in the area brought me a GLO brass cap the other day (that he found in a gravel road) as he has heard me talking about BM hunting. At first i thought it was a weird cadastral marker. After closer examination, i realized that i have an actual GLO benchmark from 1911. Examination of the topo in the find area reveals many such markers. The one i have is marked for elevation 5601; the map BM at the found location indicates 5600 feet, i suppose an adjustment was made to GLO or BLM data here.

Coordinates as determined from google earth are N41° 50' 23.94" by W116° 14' 04.36".

I wonder if anyone knows of any info on these BMs.

I have a picture but cannot post as i do not have an approved url for it.

Edited by t8r

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A friend that works in the area brought me a GLO brass cap the other day (that he found in a gravel road) as he has heard me talking about BM hunting. At first i thought it was a weird cadastral marker. After closer examination, i realized that i have an actual GLO benchmark from 1911. Examination of the topo in the find area reveals many such markers. The one i have is marked for elevation 5601; the map BM at the found location indicates 5600 feet, i suppose an adjustment was made to GLO or BLM data here.

Coordinates as determined from google earth are N41° 50' 23.94" by W116° 14' 04.36".

I wonder if anyone knows of any info on these BMs.

I have a picture but cannot post as i do not have an approved url for it.

 

It appears to be this one.

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A friend that works in the area brought me a GLO brass cap the other day (that he found in a gravel road) as he has heard me talking about BM hunting. At first i thought it was a weird cadastral marker. After closer examination, i realized that i have an actual GLO benchmark from 1911. Examination of the topo in the find area reveals many such markers. The one i have is marked for elevation 5601; the map BM at the found location indicates 5600 feet, i suppose an adjustment was made to GLO or BLM data here.

Coordinates as determined from google earth are N41° 50' 23.94" by W116° 14' 04.36".

I wonder if anyone knows of any info on these BMs.

I have a picture but cannot post as i do not have an approved url for it.

 

It appears to be this one.

 

If it is indeed the correct mark that Holtie22 pointed out, why don't you go ahead and post a report for it on gc.com below, where you can add pictures of it for all us to see.

 

Since you have it in your hand, it will need to be logged as "mark destroyed".

 

http://www.geocaching.com/mark/details.aspx?PID=mu0016

Edited by LSUFan

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A friend that works in the area brought me a GLO brass cap the other day (that he found in a gravel road) as he has heard me talking about BM hunting. At first i thought it was a weird cadastral marker. After closer examination, i realized that i have an actual GLO benchmark from 1911. Examination of the topo in the find area reveals many such markers. The one i have is marked for elevation 5601; the map BM at the found location indicates 5600 feet, i suppose an adjustment was made to GLO or BLM data here.

Coordinates as determined from google earth are N41° 50' 23.94" by W116° 14' 04.36".

I wonder if anyone knows of any info on these BMs.

 

Thanks all, sorry for the multiple posts

figured out why i could not see that on scaredycat, cross state line from idaho and links don't show

now logged as destroyedd870fc65-a39c-4b2f-890e-5e098800fc0a.jpg

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Interesting, and unique (in my experience). I have never seen a GLO marker with the altitude stamped on it.

 

At least nine - those with a number for a name - of the 99 that filter out in Nevada with a "Placed by USGLO" GSAK filter have the elevation stamped. More targets for my next road trip!

 

kayakbird

Edited by kayakbird

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GLO/BLM benchmarks are rare because the primary mission was boundary identification. I had a lot of them in Yuma area where the caps were used by Reclamation and others as BM's and stamped by them, but there were undoubtedly some sitiations where elevations were important to BLM. I did a lot of control surveys for photogrammetery throughout the west with levelling, but none of my monuments were published, but other situations could occur.

 

As to the idea of calling it destroyed, I am probably not up on the latest nuances in this forum for what 'destroyed' means, but finding a brass cap, does not mean that the monument itself is lost. As a benchmark (precisely leveled elevation mark) it could probably be assummed to be destroyed, but as a PLSS corner or GLO corner or a horizontal mark the pipe may still exist.

 

We found some brass caps that had fallen off corroded, graded, or eroded iron posts (which was the standard GLO monument after 1910 or so with lost caps. Corrosive soils could erode the pipe away to ground level. Actually the soils around Yuma would erode 1910 era GLO type monuments into flakes of rust, but they still had a magnetic signature with the metal locators until they were dug up.

 

Thus the position would not be lost just because the cap was found, but obviously the vertical integrity would have been almost totally compromised.

 

- jlw

 

A friend that works in the area brought me a GLO brass cap the other day (that he found in a gravel road) as he has heard me talking about BM hunting. At first i thought it was a weird cadastral marker. After closer examination, i realized that i have an actual GLO benchmark from 1911. Examination of the topo in the find area reveals many such markers. The one i have is marked for elevation 5601; the map BM at the found location indicates 5600 feet, i suppose an adjustment was made to GLO or BLM data here.

Coordinates as determined from google earth are N41° 50' 23.94" by W116° 14' 04.36".

I wonder if anyone knows of any info on these BMs.

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