Comments: Benchmarks are round metal pieces either implanted into a rock or placed on a post where placement in solid bedrock is not feasible. These benchmarks mark altitude, latitude, and longitude, as well as other important features of the landscape. They are often found on peaks or at the junction of sections, as on a topographic map. They can be placed by the National Geodetic Survey (now part of NOAA) or by the United States Geological Survey. Some round markers bear the mark "not a benchmark" or "not a section marker" indicating that they have been placed for some other reason. There is a fine for disturbing or altering benchmarks.

Discussion: See full discussion of a benchmark vs. other forms of geographic markers.