High Quality Content by WIKIPEDIA articles! Uranium mining in Wyoming, a state of the United States was formerly a much larger industry than it is today. Wyoming once had many operating uranium mines, and still has the largest known uranium ore reserves of any state in the U.S. The Wyoming uranium mining industry was hard-hit in the 1980s by the drop in the price of uranium. When the uranium price dropped, the uranium-mining boom town of Jeffrey City lost 95% of its population in three years.