Denver: [ca. 1900]. Sheet map, 12.75 x 21.75 inches. Previously folded. Light wear and tanning at old folds; a few short separations. About very good. Item #344
A detailed, if rather crowded, blueprint map of mining claims surrounding and including the Big Bertha mine in Gilpin County, Colorado, in the first years of the 20th century. The map was published by the Bertha Gold Mining and Milling Company, and although the map is undated, we locate stock certificates that were issued by the company in 1900, and a prospectus for the operation published in 1901. The map was surveyed and drawn by Samuel A. Rank, who was employed by the U.S. Mineral Department Survey in Colorado at this time. The map shows Bertha's claims in this mining area just north of Idaho Springs with a lined shading, as well as the many other claims in the immediate vicinity, many of which overlap with one another.