A colorized postcard of the Irish Mag shaft. The front caption on the top right reads: “Irish Mag Shaft, (Calumet & Arizona), BISBEE, Arizona.” The postcard is unused, and was published on AZO Kodak paper.
The Irish Mag claim was owned by James Daly who quarreled with the Copper Queen Mining Company. They had cut down trees and were going to build train tracks through his property for the Arizona & Southeastern Railway without his input. Daly was shot though the leg by the Constable Dan Simmons who came to serve a lawsuit after Daly assaulted a Mexican worker. In the next incident, the Constable W.W. Lowther came to serve yet another suit and was shot through the heart by James Daly and died. After the murder, Daly fled from Bisbee and never returned. The rightful ownership of the Irish Mag claims went through a number of legal battles. The United States Supreme Court settled the matter on May 15, 1899 the favor of Martin Castello. The rights to the Irish Mag were bought by the Lake Superior and Western Development Company on October 24, 1899 and was acquired by Calumet and Arizona not long after. On November 4, 1899 the sinking of the Irish Mag began. The shaft was eventually sunk to the depth of 1,350 feet and had four compartments. The shaft was sunk through hard limestone, except for occasional ore bodies. Levels were driven at depths of 440, 550, 750, 850, 950, 1050, and 1150 feet. The main ore body existed north of the shaft and became the largest ore body in the Warren Mining District. The shaft was equipped with a 78-foot steel headgear, a 114-foot ore bin and a 250 hp electric hoist raising a 3 decked cage. The Oliver mine relied on the Irish Mag shaft to hoist its ore to the surface. In eleven years of operation, the Irish Mag produced 1.5 million tons of ore and was the first mine opened by Calumet and Arizona. By 1911, the Irish Mag resources were exhausted and from 1915 on it was operated under a basis of leasing. Mining operations ended in 1928. The old mine shaft of the Irish Mag remained open to the elements until 1968 when it was filled in by tailing piles.