Economic resources of the Rocky Mountains are varied and abundant. Minerals found in the Rocky Mountains include significant deposits of copper, gold, lead, molybdenum, silver, tungsten, and zinc. The Wyoming Basin and several smaller areas contain significant reserves of coal, natural gas, oil shale, and petroleum. For example, the Climax mine, located near Leadville, Colorado, was the largest producer of molybdenum in the world. Molybdenum is used in heat-resistant steel in such things as cars and planes. The Climax mine employed over 3,000 workers. The Coeur d'Alene mine of northern Idaho produces silver, lead, and zinc. Canada's largest coal mines are near Fernie, British Columbia and Sparwood, British Columbia; additional coal mines exist near Hinton, Alberta, and in the Northern Rockies surrounding Tumbler Ridge, British Columbia.