Considered to be the earliest mining district in the country, the Cerrillos mine is just south of Santa Fe in northern New Mexico. Cerrillos Turquoise is considered to be rare today, can be found in almost every color due, and can be a good high-grade stone. Pueblo Indians worked the mine for centuries before the Spanish arrived. Over two hundred dig sites have been located. One area is located on Turquoise Hill and includes the Tiffany and Castilian mines. The second area is Mount Chalchihuitl. Cerrillos was the most extensively mined of the prehistoric sites, and is the largest prehistoric mine known in North America.