Uranium Mining in Wyoming - Shirley Basin

Shirley Basin

Uranium was discovered in the Shirley Basin, Carbon County, in 1955. Production began in 1960 from underground and open-pit mines. Mining by in-situ leaching began in 1961, the first in-situ leach mining of uranium in the United States. The ore occurs as roll fronts in Eocene sandstone of the Wind River Formation, as uraninite with pyrite, marcasite, hematite, calcite, and organic matter.