It operated many uranium mines and mills in the Elliot Lake region of Ontario, Canada, including the Lacnor Mine, Nordic Mine, Panel Mine, Pronto Mine, Quirke Mine, Milliken Mine, Stanleigh Mine, and the Spanish-American Mine.
It got ownership of a uranium mill in the Ambrosia Lake region of New Mexico when it purchased the Quivira Mining Corporation from Kerr-McGee in 1989.