Molybdenum mining in the United States

In 2014, byproduct molybdenum was produced at ten porphyry copper mines, in Arizona, Montana, Nevada, and New Mexico.

The Climax mine, historically the world's largest source of molybdenum, is north of Leadville, Colorado.

The mine was a large producer in 2014, but was put on inactive status in December 2014.

A few plants do the opposite, adding other chemicals to depress the molybdenum while the copper floats.

[3] There are a number of undeveloped and currently inactive molybdenum deposits in the United States.

United States primary molybdenum production, 1920–2014 (date from USGS)
Climax Mine, 2007
The Henderson molybdenum mine is just east of the snow-capped continental divide, which appears in the background (photo taken in mid-July, 2009)