Cyprus Amax/Henderson Mine

ABOUT THE HENDERSON MINE AND MILL
The history of Colorado reflects a hard rock mining tradition dating back to the mid-1800's. The tradition began when placer miners discovered gold in Idaho Springs in 1859. Years later, gold miners discovered the Urad ore body near the peak of Red Mountain and mistakenly identified the silver gray molybdenum as graphite. Not until the turn of the century did metallurgists at the Colorado School of Mines in Golden identify the material as the molybdenum-bearing mineral molybdenite.

A company called The Primost Chemical Company produced about 450 tons of concentrate from the Urad deposit at the time of the First World War. During World War II, the mine was operated by the Molybdenum Corporation, which mined approximately 71,000 tons of molybdenum ore at Urad, averaging 200 tons per day.

The Urad Mine changed hands again in 1961 when American Metals Climax, the newly formed parent company of the Climax Molybdenum Company, took an option on Urad. Originally, the mine was bought as a short-term investment. However, the "short-term" thinking changed when further exploration revealed 300,000,000 more tons of ore under the original ore body. This huge new find was named after Robert Henderson, a former Resident Manager at the Climax Mine and Vice President of Western Operations, Climax Molybdenum Company.

Development of the Henderson mine began in 1967. In July 1976, after spending more then $500,000,000, the first ore rolled from the mine to the mill. The Henderson Mine and Mill is the largest privately financed construction project in Colorado.

Construction of the mine and mill includes many accomplishments. The mine is one of the first to use a rubber-tired, mechanized mining system underground. A major engineering and construction accomplishment was the driving of a 9.6 mile long haulage tunnel underneath the Continental Divide. The tunnel, combined with a five-mile surface railroad, connects the mine in Clear Creek County to the Mill in Grand County. By highway, the mine and mill are separated by approximately 60 miles. Constructing the mill in the Williams Fork Valley provided an environmentally sound location for a tailing impoundment with a closed-loop water recycling system.

Since the mine opened, production, employment and profitability have followed highs and lows of the molybdenum industry generally. The mine and mill have been through many reorganizations, layoffs, and technical changes. These changes dramatically reduced costs and made it possible for Henderson to survive in the face of fierce competition. Now, Henderson is recognized as the lowest cost, high quality, primary molybdenum producer in the world.