What the heck is Benchmark hunting?
Benchmarks are permanently fixed metal disks found at various locations all over the United States . These disks are used by land surveyors to perform efficient surveying, engineering and mapping . Benchmarks are actually control points used for precisely establishing an elevation or location in latitude and longitude . Benchmarks were first used in the United States in 1807 when president Thomas Jefferson Established The National Geodetic Survey, our Nation's first civilian scientific agency.
I enjoy finding benchmarks because I'm usually traveling to a place I have not been and sometimes the places benchmarks are found have some historical value. The photograph below was taken in Leadville Colorado. I found this benchmark set in a windowsill of a very old building in the center of town. A group of surveyors were working on the corner as I was looking for this disk. They were very excited to explain to me how they were using the disk in their calculations, though I couldn't repeat a word of it . All thought benchmark hunting was a great hobby.
After checking out this photo and Data Sheet use the following links to view my finds and other photographs.
The Following is part of the information contained in a NGS Data Sheet for a Benchmark