+bigthicket Posted September 21, 2010 Posted September 21, 2010 On a US Dept. of Agriculture forest service map I've come across a USLM; it is designated by a solid triangle. According to the map legend this is a US location or mineral monument. On a 24k Geological Survey topo it's shown as a USMM. Can anyone tell me the significance of this type of monument, particularly as it relates to benchmarks? I would like to know about it before I attempt to locate it......it'll be quite a hike. Thanks Quote
southpawaz Posted September 21, 2010 Posted September 21, 2010 Location Monuments and Mineral Monuments are cadastral (boundary related) monuments. If a survey of a mining claim or other survey was to be performed in an area that had no cadastral monuments (i.e. PLSS section corners) within 2 miles, a Location Monument or Mineral Monument could be set to serve as an initial point for the survey. Cadastral monuments have little to do with the geodetic marks that comprise the database of benchmarks that are loggable on GC.com. Occasionally the position and/or elevation of an existing cadastral monument was determined by a geodetic survey crew to save having to set their own monument, so there are exceptions. Having said that, I'd encourage you to check it out anyway. They tend to be older chiseled stone monuments, which I always enjoy finding. I use National Geographic TOPO to scale the coordinates of the point on the map, and use that as search point. Let me poke around and see if I can find a photo of one I've posted previously. Quote
+bigthicket Posted September 21, 2010 Author Posted September 21, 2010 Found it: I appreciate the info. I'll definitely look for it. Thank-you Quote
+billwallace Posted September 22, 2010 Posted September 22, 2010 I appreciate the info. I'll definitely look for it. Thank-you Waymark it and post a picture here - those are cool (he says as he unfolds his national forest map)... Quote
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