The Mount Emmons molybdenum deposit is located beneath the upper south slope of Mount Emmons, approximately 6 km northwest of the town of Crested Butte, Colorado (fig. 1). Mount Emmons lies in the Ruby Range, which is a part of the West Elk Mountains. The Elk Mountains are situated a short distance to the north and northeast.
Mining of precious metals, base metals, and coal in the Crested Butte area has been nearly continuous since the 1870’s. Molybdenum was first reported to occur in the region at Paradise Pass and at “Treasury Mountain” (now Treasure Mountain) by Worcester (1919). Extensive regional exploration for molybdenum has occurred primarily in the past 20 years.