2017-07-192022-02-032017-07-192022-02-031917https://hdl.handle.net/11124/171106Scale 1:1,200. 1" = 100'. Scale 1:2,400. 1 inch = 200 feet.Maps area in the Grand Island mining district.Negative blueline.Includes "Cross section of Windy Tunnel," scale 1 inch = 300 feet (1:3,600).Covers parts of Boulder County, Colorado. Covers parts of the Tungsten quadrangle, Colorado. Commodities mined: Tungsten.87 x 48 cm50 x 48 cmmine mapsengMining claims -- Colorado -- Boulder County -- MapsMines and mineral resources -- Colorado -- Boulder County -- MapsTungsten ores -- Colorado -- Boulder County -- MapsStillImage