The Old Hat Mining District in Pinal County, comprising the famous gold mines including the Collins, Mohawk and Mammoth, saw its earliest beginnings with the Hackney claim discovered in 1879 by Charles Dyke and T.C. Weed.
This area contained an oxidized outcrop of quartz that became known later as the Collins vein.
The town of Mammoth was established on the west bank of the San Pedro River and was named such on account of Frank Schultz, an Austrian immigrant who also christened his mining claim as the “mammoth lode gold vein” in 1882.
The town hosted a stamp mill that serviced the mines around the camp of Schultz , 3 miles to the southwest.
The mill serviced George N. Fletcher and his two sons, who acquired the Mammoth claims in 1885.
Operations halted for several years and remained sporadic through the next decade, when the Mammoth claims were leased by Fletcher to the English firm Mammoth Gold Mines Limited.
A U.S. post office opened at Mammoth in 1887. By 1890, the town of Mammoth had a population of 700.
Early ore transport from the Mammoth claims at Schultz to the Mammoth Mill was by 20-mule-team wagon operated by William Neal from nearby Oracle.
However, the consolidation of the Mammoth and Collins operations by Mammoth Collins Gold Mines, Ltd., led to the investment in a two- and three-quarter-mile-long aerial tramway used to transport gold ore from the Mammoth claims to the mill.
The tramway consisted of fifty 560-pound cars that also transported water from the San Pedro River back to the mines.
With ore assaying around $15 per ton, it required the need to process by volume and necessitated a 30-stamp mill operated by 20 men.
The Mammoth Mill was increased to 70 stamps in 1900.
At 820 pounds apiece and at a rate of 96 drops per minute, each stamp made a formidable noise that carried several miles.
A 200-ton-per-day cyanidation plant known as the Mammoth Cyanide Works was constructed just north of the Mammoth Mill.
Operated by the Mammoth Collins Gold Mines, Ltd., its purpose was to recover gold from the nearby mine tailings.
Acquired tailings were sent to large wooden tanks where the gold was dissolved in a cyanide solution and recovered through precipitation on zinc shavings.
Epes Randolph, railroader and mine investor, also had a stake in the development of the Mammoth Mines.
Through the Mammoth Development Co., whose name was changed to the St. Anthony Mining & Development Co., in 1918, the interest was in molybdenum extracted from wulfenite deposits.
Molybdenum was used as a steel hardener and was an attractive commodity to meet the industrial need during World War I.
Shortly after the outbreak of the war, the Arizona Rare Metal Co., whose partners were Frank H. Hereford and William Jennings Bryan, Jr., were already active in working 250,000 tons of old mill tailings at Mammoth.
Their plant included seven concentrating tables that produced a daily output of two tons of concentrate. Valued at $300 per ton, the concentrate average 22 percent molybdenum and 62 percent lead, with a small percentage of vanadium and tungsten.
Freight teams hauled the concentrate to Tucson and then shipped by rail for refinement in Pittsburgh.
The culmination of World War I in 1918, followed by a decline in the molybdenum market, caused mining operations around Mammoth to cease.
Processing facilities, including the Mammoth mill were shut down, dismantled and sold.
Total production of the Mammoth-Collins Mine from 1916 to 1919 included 10,450 ounces of gold and 447,876 pounds of molybdenum.
A cessation of mining activity occurred over the next 20 years until an increase in the market price of gold brought renewed activity by the Mammoth-St. Anthony, Ltd.
By World War II, the Old Hat Mining District metal production included vanadium, lead, silver and zinc, and the old mining camp of Schultz became known as Tiger.
