...
Robert Metcalf is credited with having filed the first mining claim in the area in 1864. A few years later, he sold partial interests in the claims to merchants Henry and Charles Lesinsky. A crude refinery was built nearby Clifton, Arizona to which, the mined ore was transported by “burro train.” The first railroad built in Arizona was constructed to run from Clifton to Metcalf. This was about five miles.
On November 12, 1958, Kennecott Copper Corporation Ray Mines Division, as part of a 40 million dollar plan, opened a new copper smelter and LPF (Leach-Precipitation-Floatation) Plant in Hayden, Arizona. This was the first in Arizona and second of its kind in the whole world. The new copper mining process helped to conserve the state’s natural resources and reduce the cost of mill copper by withdrawing every bit of raw copper ore. This improved Arizona’s strength and position in the copper market.