The Uravan mineral belt is an
arcuate zone of uranium-vanadium deposits in San Miguel, Montrose, and Mesa counties, Colorado, and
Grand County, Utah. It was the area most productive of uranium in the United States in the early 20th century. The mineral belt includes the
Slick Rock, Gypsum Valley,
Uravan, and
Gateway mining districts. Uranium mining in southwest
Colorado goes back to 1898, when a miner dug of yellow ore that tested high in
uranium and
vanadium out of a deposit at
Roc Creek in
Montrose County, Colorado, and shipped it to
France, where M. M. C. Friedel and E. Cumenge identified the new mineral that they named
carnotite. The mineral was mined for its
vanadium, with
uranium as a byproduct. Although
radium had been discovered in 1898, it had been derived from
pitchblende, and the radium content of
carnotite was not known.
Carnotite was suspected to contain
radium as early as 1903, on the basis of the anomalously high radioactivity of carnotite ores. But it was not until 1911 that the
radium content of
carnotite was confirmed by the
Marie Curie laboratory in
Paris. Although no more than a trace of
radium was present in the ore, newly discovered medical applications had made radium worth $100 per milligram (equivalent to $ per milligram today), making the radium in the carnotite ore worth much more than the
vanadium or
uranium. Once
carnotite was known to contain
radium, prospectors rushed to the
Colorado Plateau of southwest
Colorado and adjacent southeast
Utah, and found
carnotite-bearing sandstones of the Jurassic
Morrison Formation in
Mesa,
Montrose, and
San Miguel counties in Colorado. The carnotite was at first shipped to Europe for processing, but by 1913, the
Standard Chemical Company had built a radium processing plant in
Montrose County that had become the world's largest supplier of
radium. The
Uravan mineral belt of Colorado and Utah supplied about half the world's
radium from 1910 to 1922, and
vanadium and
uranium were byproducts. The mines were forced out of business in 1923, when rich pitchblende deposits in the
Belgian Congo forced down the price of
radium. Mining revived in 1935 when the price of vanadium rose, and boomed after
World War II when the government stockpiled
uranium for nuclear weapons programs. The Uravan mineral belt contains what was the last producing uranium mine in the state, the Topaz Mine, part of the Sunday Complex near
Uravan, Colorado, which was closed down on 18 March 2009 by then owner
Denison Mines due to depressed uranium prices.
Energy Fuels Inc. has applied for a permit to rehabilitate and begin pilot production at the Torbyn mine, a former uranium producer in
Mesa County just east of
Gateway. ==South Park==