Uranium in the Sanostee district, San Juan County, New Mexico

The Sanostee district (also known as the Chuska district) is located within the Navajo Indian Reservation, San Juan Basin, San Juan County, New Mexico. On the Reservation all prospecting, leasing and mining was controlled by the Navajo Tribal Council and the Bureau of Indian Affairs. All prospectors had to have a permit. Uranium ore has been produced from the Salt Wash and Recapture Members of the Jurassic Morrison Formation and a small amount of ore has been mined from the Jurassic Todilto Limestone. Total production from the district amounted to 139,399 short tons of ore grading 0.12% U3O8 and 0.14% V2O5 and containing 332,721 pounds of U3O8. During the period 1952 through 1982, the large underground mine on Enos Johnson’s mining permit, west of the village of Sanostee, produced 136,665 short tons of ore that averaged 0.12% U3O8 and contained 325,927 pounds of U3O8. Ores that were analyzed for vanadium averaged 0.14% V2O5. This production makes the Enos Johnson mine the largest uranium mine in New Mexico, outside the Grants uranium district. It is likely that additional small deposits could occur in the Sanostee district. However, the Navajo Indian Reservation now has a moratorium on any uranium exploration and mining within its boundaries. Furthermore, the known deposits in the Sanostee district were relatively small compared to the larger more extensive deposits in the Grants uranium district. It is unlikely that any of the deposits in the Sanostee district will be mined in the foreseeable future.