Listing of tungsten mines with location, owner, production, workings, ore occurrence, potential, last operator, and map sources. 78 pages. Digital PDF download. MI-04D.
From the Introduction:
The history of tungsten in the United States is a history of “boom and bust,” with periods of intense exploration and production followed by periods of almost complete abandonment of the mines. During these periods of non-operation, facts relating to the mines often become distorted or completely forgotten; indeed, the actual location of mines sometimes becomes lost, as witness a large group of small mines listed in this report, mines which were designated prospects upon a large agricultural patent, but which now appear to be completely lost, unknown even to the owning company and to its previous mine superintendents.
For reasons such as this, the Metal Mining Fund of the State of Colorado has deemed it advisable to compile certain basic facts concerning the tungsten mines of the state. This tabulation is not to be considered an evaluation of any property, but is limited to brief essential information which would offer a starting point in future mine investigations. An effort has been made to tie each property to some generally known landmark, so that its position may be recognized even after the lapse of several years.
Information tabulated in this report is as of January l, 1960. It will be realized that ownerships change from time to time, and that, in periods of production, the physical workings of the mines are gradually altered, as well as records of production.