Brief history of Turquoise mining and Turquoise Hill
— Homer E. Milford

Turquoise was mined by Native Americans in the Southwest for a thousand years but Europeans operated mines in New Mexico specifically for turquoise only for a few decades when prices were unusually high. The old turquoise mines in the Cerrillos Hills south of Santa Fe were the most famous turquoise mines of the 1800s. Of these mines the Tiffany and Old Castilian mines on Turquoise Hill produced the majority of the quality stones.