The Historic Lisbon Valley Mining District is located southeast of La Sal in San Juan County, Utah. Copper was discovered in the area in 1892 and mining activities increased in the late 1920’s after the additional discovery of uranium and vanadium. Tronox operated in the Mining District and the area was a major producer of both uranium and copper until historic operations in the district ceased in the late 1980’s.
Waste from these historic mining operations are found at the soil surface in recreation areas and in several ephemeral drainages and arroyos. Visitors to the historic mines may be exposed to hazardous substances and contaminated mine waste may be eroded and released downstream during seasonal storms and large run-off events.