Located 56 miles southwest of Flagstaff on the east slope of Mingus Mountain — a 1,750-million-year-old volcanic tuff — the town of Jerome and its surroundings were once known as one of the greatest copper-producing areas on the planet.
But even in the 1800s, the area was not new to mining. The Tuzigoot Indians mined the oxidized copper ore “azurite” and “malachite” for jewelry and dye. Old workings and mining implements were discovered by the Spanish explorer Antonio de Espejo in 1585 and by Juan de Oñate the following decade.
Mining began in earnest around Jerome with the arrival of Al Sieber — a former scout of Gen. George Crook — who filed the first claim on Mingus Mountain in 1876.
Additional claims followed, including those of M.A. Ruffner and Angus McKinnon. The town of Jerome, at 5,435 feet in elevation and established Sept. 10, 1883, was named after Eugene Jerome, a New York attorney and one of the organizers of the United Verde Copper Co., which financed further mining development.
Sen. William Andrews Clark, a copper magnate from Montana, is credited with having developed the United Verde Mine in the late 1880s.
He acquired the mine when copper prices had dropped and Eastern investors were eager to sell. Phelps Dodge & Co. was prepared to buy the property, but was beaten to it by Clark, who acquired the mine for $275,000.
What became known as the United Verde mine was referred to by the local miners in the late 19th century as the “Big Hole” because of its numerous shafts, stopes, tunnels and miles of drifts. By 1900, the mine was averaging $1 million of copper a month.
One of the signature events in the United Verde mine’s history was the fire of 1894. Its scope and intensity caused it to spread from the upper levels of the mine down to the 900-foot level.
The fires were difficult to extinguish, and burned underground for several decades because of the high sulfur content in the massive sulfide deposits of pyrite, chalcopyrite, sphalerite and galena that, when mixed with heat and oxygen, caused spontaneous combustion.
Rare minerals, including voltaite and lausenite — an iron sulfate hydrate — were formed as a result of the fire and are only found at Jerome. The fires made it difficult to access the 10 million tons of ore below the surface.
Clark resolved the ore-accessibility challenge by establishing an open-pit mining operation that ran from 1918 to 1940. He had previously invested $1 million in moving his smelter operations to the new town of Clarkdale in 1912.
Clark bought water rights from several ranches in the Verde Valley to supply his new company smelter town. The Verde Tunnel & Smelter Railroad serviced the smelter and mines as part of the Hopewell Tunnel system. The Verde Valley Railway connected Clarkdale to the Santa Fe Railroad at Drake.
The United Verde Copper Co. surpassed the Copper Queen in Bisbee as Arizona’s top-producing copper mine in the early 1900s. It was truly a family enterprise, having avoided mergers and partnerships.
Sources: Lon Abbott and Terri Cook (2007), “Geology Underfoot in Northern Arizona”; E.M.J. Alnius (1968), “A Brief History of the United Verde Open Pit, Jerome, Arizona”; C.A. Anderson and S.C. Creasey (1958), Geology and ore deposits of the Jerome area, Yavapai County, Arizona: U.S. Geological Professional Paper 308; Carlos A. Schwantes (2000), “Vision and Enterprise: Exploring the History of the Phelps Dodge Corporation”; Robert L. Spude and Stanley W. Paher (1978), “Central Arizona Ghost Towns.”
William Ascarza is an archivist, historian and author. Email him at email@example.com