Platt, Howard2017-07-182022-02-032017-07-182022-02-031898https://hdl.handle.net/11124/171101Photocopy of original.Color.Covers parts of Boulder County, Colorado. Covers parts of the Tungsten quadrangle, Colorado.88 x 72 cmmine mapsengMining claims -- Colorado -- Boulder County -- MapsMines and mineral resources -- Colorado -- Boulder County -- MapsWorking map of the Twin Lakes Con. Placer Mg. CompanyStillImage