Colorado Mineral Surveys - Example Field Notes of the First (1867) and Last (2005)

The Denver National Archives reopened last month so I had an opportunity to peruse the original field notes for Colorado mineral surveys. The first mineral survey in Colorado Territory was conducted and approved in November, 1867. The survey was of the Ellieth Lode, Sur. No. 37 in the Gregory Mining District of Mineral District No. 1, Gilpin County. The field notes do not specify the instrument used to conduct the survey, but if I were to guess, I'd say a compass and Gunter's chain. For this survey conducted by Hal Sayr, U.S. Deputy Surveyor, the units are chains, not the common units for mineral surveys of U.S. Survey Feet.

The last mineral survey in Colorado was conducted in September 2005 and approved on March 22, 2006. The survey was of the Robin Redbreast, President, Senator, and Governor lodes, Sur. No. 20931 in the 7th Mining District, Hinsdale County. The field notes describe the instrument used to conduct the survey as,

Trimble Navigation, Model Number 4000 ssi Global Positioning System (GPS) base receiver....and a Trimble Navigation, Model Number 5700....GPS rover receiver.

This is the only instance in Colorado where GPS instruments were used to conduct a mineral survey under an official BLM mineral survey order. If you read the introduction to the field notes you will notice that it was used as the template for the Appendix III - Specimen Field Notes - Mineral Survey on page 452 of the 2009 Manual of Instructions (note the serial numbers of the base and rover being only different by 1 digit from the field notes of Sur. No. 20931).

While I didn't start out with a compass and Gunter's chain, I began my survey career in 1973 as a rear chainman for the Nebraska Dept. of Roads. The equipment I started out with were a Lufkin 100 ft. cut chain and K&E Paragon transit. Now I use a robotic total station and GNSS receivers to conduct my resurveys. Quite the journey! 🙂