Uranium History

The History of Uranium discovery in the La Sal area dates from 1880, when settlers knew that the local natives obtained a yellow pigment (uranium minerals such as carnotite) from nearby sources.  Prior to World War I, mining for vanadium began at La Sal Creek, just east of La Sal, and north of the Wray Mesa Uranium exploration Project.  In the early 1940’s exploration programs were started and development of uranium deposits was stimulated under the Manhattan Project.  The next 15 years saw active mining and numerous discoveries in the La Sal Creek area; however, the main mineralized trend at La Sal Channel near the town of La Sal was a later discovery in the late 1960’s.

The discovery of the Pandora ore body in the late 1960’s marked the beginning of the definition of the main La Sal mineralized belt.  During the 1970’s and early 1980’s the La Sal district remained very active with mines being operated by Union Carbide Corporation and Atlas Minerals.  These mines included Beaver Shaft, Mike, Snowball, Hecla, La Sal and Pandora.  Production from the district continued until the mid 1980’s.  In 2006, Dennison Mines reopened the Pandora mine and is currently conducting underground development and small scale mining, shipping ores some 60  miles to Blanding, Utah for processing.  The La Sal- La Sal Creek district has produced approximately 6.4 million pounds of U3o8, at an average grade of approximately 0.32% U3O8.

Uranium and vanadium ores were first discovered in the nearby Lisbon Valley (Big Indian District) area in 1913 in Cutler Formation sandstone outcrops.  The Lisbon Valley district has undergone two major uranium boom periods, in the 1950’s and then again in the 1970’s.  Following the formation of the U.S. Atomic Energy commission in 1947, a national defense procurement program was implemented due to the urgency of the Cold War nuclear arms race.  Small shipments from various mines ensued.  Fierce competitor exploration and development activity began in 1953, with the discovery of the Mi Vida ore body by geologist Charlie Steen.  Steen, looking for oxidized uranium mineralization (carnotite), was the first to discover unoxidized ore in the Moss Back Member rather than in the Cutler sandstone.  His Mi Vida Mine heralded the beginning of the big uranium discovery boom of the 1950’s.  A second period of intense exploration activity ensued from the 1970s to 1981 following the curtailment of AEC-government purchases at the end of 1970, escalating uranium commodity prices, and the new entry into the uranium purchasing market by electrical power generation companies.  Approximately 78 million pounds of U3O8 have been produced from the Lisbon Valley district from 1948-1988, and accounts for approximately 12% of total US production and for 80% of all uranium ore mined in Utah during that period (Chenoweth, 1990).  The Lisbon Valley District is dominantly a uranium district with only minor amounts of vanadium, and the host rocks are Permian and Triassic age rocks; whereas, the Wray Mesa project area and the La Sal district most resemble the uanium-vanadium mineralization of the Uravan Mineral Belt.

The Uravan Mineral Belt is located 40 miles to the east and southeast in Montrose and San Juan Counties.  The Uravan Mineral Belts in composed of several areas of historical mining of uranium-vanadium ores derived fro the Salt Wash member of the Morrison Formation, a similar geological environment to the La Sal District and the Wray Mesa Uranium Exploration Project.  The historical production from the Uravan Mineral Belt is approximately 69 million pounds of U3O8 and 360 million pounds of V2O5

The entire Colorado Plateau region including the La Sal, Lisbon Valley, and Uravan Mineral Belts had been undergoing a third period of renewed exploration activity and mining as a result of the dramatic increase in U3O8 prices.  The uranium commodity price increase had resulted in a re-examination of smaller uranium deposits previously considered uneconomic in grade or tonnage and initiated the exploration activity in the Wray Mesa area and La Sal District.

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