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Yet another benchmark database - BLM???

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Found this benchmark yesterday.




I kind of remembered this benchmark being here from a previous visit to this mountain top.




You can see it's location in the second image. It is set near the peak of Bird Ridge (lower left hand corner). The benchmark reads 'Dept. of the Interior - Bureau of Land Management'. I knew there were Corps of Engineer benchmarks, but didn't know about these.


So, I guess there is yet another database of benchmarks out there for us to hunt up. Is there an official list of these available to us?

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Please remember that the General Land Office, and its successor, the Bureau of Land Management, are within the Department of the Interior, while the United States Coast and Geodetic Survey, and its successor, the National Geodetic Survey, are within the Department of Commerce. These organizations have entirely different purposes. The geodetic markers set by the USC&GS & NGS serve the mapping, engineering and construction industries, while the cadastral markers set by the GLO & BLM pertain to boundaries of land and govern property rights, serving the mining, ranching, forestry and oil & gas industries, as well as private land owners.

The BLM operates primarily in the Public Land States of the west, not in Kentucky, Tennessee, Texas or the Colonial States. Since it takes at least 8 markers to encompass one square mile, most of which are not disks, it administers millions of markers, covering over 400,000 square miles. While some of its markers are for special projects, many indicate property boundaries between public and private land. The difference between property markers and benchmarks should be understood. While benchmarks are very important to the nation's economy and the general public, property markers are of even greater importance to those whose rights depend upon them. Although the Wild West is long gone, miners, ranchers, loggers and oilmen still often go about armed and have been known to draw down on anyone, even surveyors acting legitimately, found snooping around the corners of their property.

The BLM website, www.blm.gov, contains a wealth of information about its mission and geographic data. The information is public, but some of it requires GIS software to access. While the information is freely available, it should be used prudently, in safe areas familiar to the user, such as National Parks, in order to avoid conflicts. Any use which may lead to even accidental trespassing, and the possible consequences thereof, is not recommended.

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As much fun as benchmark hunting can be, we all need to realize that this has a little different impact than normal geocaching. NGS and BLM markers are of vital importance to the surveying industry, and therefore to many construction and land use industries as well (and by an even further stretch of the imagination the entire economy). In many locations, suburban Detoit for example, the PLSS (Public Land Survey System) and surveyors depends on NGS and LCRC records to perpetuate boundaries in neighborhoods, condos, and unplatted land. Without these markers, and the surrounding evidence of them (witness marks), knowledge and historical surveys now used as a basis for our land division would be lost, and this evidence cannot be replaced.

I have to admit that when I heard of this benchmark hunting i thought it was a bad idea. However, NGS benchmarks tend to be pretty hardy markers, and as long as people know why they're there (not for enjoyment!), they can be enjoyed and used.


Or....we could take this idea even further.... everyone down to the Register of Deeds, lets raid the LCRC's and go open some monument boxes. "Hey! What's this cap thing on this iron rod in the ground inside a monument box in the middle of the street? Better take it off and look at it! What do you mean that was set by a Professional Surveyor as a property corner? You mean there's more around here? Cool! Let's start collecting these cap things"


Better stick to ammo boxes and McToys.....

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I don't believe people are hitting them with clubs or poking them with long, pointy objects. At worst, someone may brush some dirt off of it (or *gasp* pour water on it before taking a photo).


Based on the recovery efforts of some geocachers, it seems like we're doing more good than harm, here. But perhaps time will tell.


Obviously, if a benchmark is on private propery (or off-limits locations), you don't have the right to disregard existing laws.


Jeremy Irish

Groundspeak - The Language of Location

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