(Colorado – Idaho Springs) Map of Portions of Lower Clear Creek and Gilpin Counties Showing Mining Claims in the Vicinity of Idaho Springs Colorado from Official Surveys and Records by James Underhill, Mining Engineer-U.S. Dep. Min. Surveyor
This is an extraordinarily detailed claim map of the region from Idaho Springs to Central City and west to Empire and Downieville. Prepared by James Underhill, this the map was drawn to promote the Tunnel Lines of the Big Five, but this is different than the larger and more common version of this map. This is our first encounter with the map is this size and it comes from an estate of a close friend of Mr. Underhill.