Located three miles north of Superior in Pinal County, the Silver King Mine was once the richest silver mine in Arizona, producing high-grade silver along with smaller amounts of gold, copper, zinc and lead.
In 1872 a soldier named Sullivan discovered silver sulfide nuggets while building a supply road popularly known as the Stoneman Grade. The road was named after Gen. George Stoneman, whose forces were stationed in the area to protect miners and settlers from the Apache. The road later connected the mines around Superior through the Pinal Mountains to Globe, roughly paralleling the future Miami Superior Highway 60.
Although the future Silver King deposit was kept confidential, Sullivan did tell of its existence — though not its precise locality — to rancher Charles Mason. Mason and a group of prospectors including Ben W. Regan, William H. Long, and Isaac Copeland made a second discovery there in March 1875, initiating the beginning of the Silver King Mine and the Pioneer Mining District.
On April 30, 1877, the San Francisco Stock Exchange acknowledged the sale of 33 tons of ore averaging $4,650 to $1,230 per ton from the Silver King. The monthly average was 30 tons.
Sullivan had long since disappeared, then returned in 1882 and upon proof of his identity and affiliation as the mine’s first discoverer, was employed by the Silver King Mining Co.
Some of the remaining camels left over from a failed camel integration experiment conducted by the U.S. War Department in 1855 transported ore from the Silver King Mine down the Gila River to Yuma in 1876. The ore was shipped to San Francisco for processing before the establishment of Picket Post in 1878, later changed to Pinal.
Highgrading (theft) among the teamsters often occurred during the transport of ore between the mine and town. It was not uncommon for a driver to scold his mules while in transit and toss a chunk of high-grade silver ore at them while passing an acquaintance who naturally picked up the discarded ore and divided its worth with the teamster.
Located at the northeastern foot of Picket Post Mountain on Queen Creek, Pinal served as a milling town for the ore mined at the Silver King Mine five miles away.
Pinal claimed a population of 2,500 and 123 buildings, including a school, several churches, saloons, hotels and breweries.
Because of declining silver market prices, the cost of wood to supply the steam engines at the mine and its machinery, and rising costs of processing, the Silver King Mine was closed in 1888.
By that time the principal shaft of the Silver King Mine reached a vertical depth in excess of 700 feet. The town tied to the production of the mine was abandoned several years after the mine closed.
The total value for the silver mined from the Silver King Mine was approximately $6.5 million, which would equate to $300 million in 2014.
Many attempts over the past 100 years to reopen the mine failed because of lack of capital to finance the removal of water and proceed with production.
During the 1970s and ’80s limited cyanide leaching was implemented on the mine’s tailings with some success.
The legacy of the Silver King as Arizona’s premier silver mine continues. Right now the Silver King Mine includes nine claims and is owned by the Integrity Mining Co., which concluded through recent assays the potential of mining $2.5 million in silver at the mine tailings and dumps of the Silver King.
Plans entail reopening of the underground mine, which may reestablish the mine’s preeminence in Arizona’s silver production in the 21st century.