The Idarado opened up many mines in Red Mountain District and made them successful again. In the1880’s there was a mining boom on Red Mountain Pass. The Yankee Girl Mine was the most famous. This early mining boom was mostly over by the mid 1890’s. Later, in 1943, the Idarado mine leased its property to the US Government to reopen the Black Bear mine through the Treasury Tunnel. The tunnel went for 5 miles from the top of Red Mountain Pass though the mountains, to Telluride. The Idarado mined minerals for World War II. Minerals from the mine were made into metal for making planes, ships and tanks.In 1945 the Treasury Mill was rebuilt to mill lead, zinc, and copper ore. In 1946, a new crusher was installed at Idarado to increase ore production. By 1947, the Treasury Tunnel to Telluride was complete. In 1954, a big fire burned the Idarado buildings and they were rebuilt. By 1956, a new mill was built near Telluride. Red Mountain mill was shutdown. Idarado kept mines in Ouray going.
by Ty Edder and Rachel Jennings