McCallum, Jean2017-07-192022-02-032017-07-192022-02-031916https://hdl.handle.net/11124/171120Scale 1:480. 1 inch = 40 feet.Blueline print, colored in pastels.Photocopy.Shows "elevation along plane of vein showing filled stopes, empty stopes, drifts and ore blocks," in area in Grand Island mining district.Inset gives table of ore reserves.Covers parts of Boulder County, Colorado. Covers parts of the Nederland quadrangle, Colorado. Commodities mined: silver, lead/zinc, gold, and uranium.41 x 55 cmmine mapsengMining claims -- Colorado -- Boulder County -- MapsMines and mineral resources -- Colorado -- Boulder County -- MapsStillImage