Mining Claim Monuments – With Photos

This section includes photographs and descriptions of various types of claim and survey monuments including, marked mineral monuments, suspected mineral monuments, bench marks, marked patented claim corners, suspect patented claim corners, unpatented claim corners, and unpatented discovery monuments (DM’s) a/d/a unpatented location monuments (LM’s).

Patented claim owners may find these photographs useful to locate their claims, however, only a claim monument that is clearly identified as a specific patented claim corner should be relied on.  Furthermore, unless marked as being set by a Professional Land Surveyor, all monuments should be considered suspect.

Many corner monuments set on patented claims in the mountains of Colorado are described as a wooden post, set in a rock cairn, with the mineral survey and corner number inscribed on the post. In timber country the posts have mostly rotted away, leaving unmarked rock cairns as evidence.  Identifiable wooden corners are actually more prevalent above timberline.


Rock Corner 2 - MS 6230

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This rock monument marks corner No. 2 of Mineral Survey 6234 in a mining district in  western Utah.

Inscribed wooden 6x6 pat corner

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6×6 post with mineral survey and corner numbers inscribed on the post.  It was mapped as a patent corner because it fit at the correct bearing and distance to other marked corners of the patented claim.

Patent corner evidence

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This monument was mapped as a patent corner. The inscription on the post clearly shows the mineral survey number and the corner number, and the position fit well with other corners of the patent.

Patented claim, steel pipe, stamped.

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A steel pipe and cairn with the mineral survey number and the corner of the patented claim stamped into the  pipe.  This was mapped as a corner of a patented claim. It fit well with the mining workings shown on the mineral survey and also with other claim corners with similar monumentation.

Recent surveyors cap

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A cap set by a Professional Land Surveyor at the corner of a patented claim that was originally surveyed in about 1910. No evidence of the original monument was found on the steep slope where this cap was set, but rock cairns generally collapse and disappear on steep slopes.  The surveyor who set this cap apparently based the position on bearing trees and other found corners of the patent.  This would be mapped as a found patent corner.


not a reliable corner

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Steel pipe roughly in the correct position of a patent corner as related to other found corners.  This was not mapped as a patent corner since there were no definitive markings.

Rock Crn-unmarked

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Cairn that fits the position of a patented claim corner.  As there were no markings found, and no inscriptions on the rocks examined, this cairn was not mapped as a patented claim corner.

scribed post

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Although this post was inscribed with a mineral survey number and a corner number, there was no cairn or indication of where it had been set.  It was not mapped as a found patent corner.

rotted scribed post

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This rotted post and cairn fit well with the position of the patented claim corner as shown on the mineral survey. However, it was not mapped as a definitive patented claim corner.  Although inscribed, the mineral survey and corner number were not legible on the post.


Unpatented 4x4 corner

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I personally set this 4×4 post and cairn in Utah in 1980.  It is marked with an inscribed aluminum tag as a discovery monument, which is also evidenced by the hole drilled in the post for the insertion of the Location Notice.

2x2 claim post

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This is a typical unpatented claim monument as set today. Generally a 2×2 wooden post is set, with an inscribed aluminum tag.  This particular post is a discover monument a/k/a location monument.  The Notice of Location was placed in the film cannister  which is wired to the post.

short post in Utah

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Claim monumentation requirements in Utah are lax. Consequently, unpatented claims are poorly monumented. This is a 2 foot tall 2×2 claim corner.  I have found survey lath and even pin flags used as claim monuments in Utah.  Furthermore, in Utah many of the locals fail to even mark their posts, set their posts in the ground, or even set their posts at all.  Most other states have tougher requirements, with some requiring 4×4 posts.

various post examples

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You never know what you might find as a unpatented claim corner.  Most states allow a 2×2 post, or a steel fence post, or a natural post, all as shown here.  Twenty or thirty years ago 4×4 posts were the norm or requirement in many states, but now are rarely used.

Rock crn for claim monument

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This is an example of a unpatented claim monument in Arizona.  Most states allow a rock cairn of a prescribed sized as a claim monument, but they are most common in the desert states.  They are generally marked by a paper in a tobacco can, or jar, or just placed under a rock.

Post type I useI generally use a 4′ x 2×2 post, with the top dipped in Rustoleum, and marked with a thicker oval “racetrack” tag. Here’s one set at 12,000 feet in the San Juan Mountains of southwestern Colorado.

To the right of the lake is a rock glacier.

Weathered 4x4

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This is a 4×4 after being weathered above timberline for 100 years or so.  It is probably a patented claim corner but could not be verified as such.


Mineral Monument

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Mineral Monuments (USMM) a/k/a Location Monuments (USLM) were set in regions with poor or unreliable survey monumentation.  This 6×6 posted is inscribed as USLM Carbon Lake and also is marked by an inscribed aluminum tag. San Juan County, Colorado.

Rock Mineral Monument

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A Mineral Monument set in Utah. Reportedly in the La Sal Mountains, Grand County.


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U.S.L.M Excelsior. Originally described as a cross inscribed on a rock face, but remonumented by the BLM in 1983. San Juan County, Colorado.

Not a Min Mon - Bench Mark

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This is not a Mineral Monument or a Location Monument, although is set within twenty feet of the described position of such.  This is a benchmark set by the USGS in 1951.  The original Mineral Monument, set in the 1800’s, was not found.  Do not confuse benchmarks for Mineral Monuments. Beaver County, Utah.


1911 Section Corner

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This is an example of a General Land Office (GLO) section corner that was set in 1911.  Notice that it shows that two section corners are offset, but it is not obvious which corner this cap marks.  In this case two caps were found, about 150 feet apart, this cap marking the corner common to sections 21 and 26.

GLO Quarter Corner

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A 1911 GLO Brass Cap – quarter corner.  Quarter corner brass caps, and the steel pipe on which they are attached, are smaller in diameter than section corner brass caps, which in turn are generally smaller in diameter than township corner brass caps.

Section Corner Brass Cap

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This section corner was out of place on a steep hillside, so was not mapped.  As can be seen, bedrock is shallow.  No cairn, or bearing references, were found evidencing the original position of the corner.

Navigating for MMs

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Searching for Mineral Monuments.