The Treadwell gold mine was on the south side of Douglas Island, east of downtown Douglas and southeast of downtown Juneau, owned and operated by John Treadwell. Composed of four sub-sites, Treadwell was in its time the largest hard rock gold mine in the world, employing over 2,000 people. Between 1881 and 1922, over 3 million troy ounces of gold were extracted. Not much remains today except for a few crumbling buildings and a "glory hole". Although John Treadwell had twelve years of experience in both placer and lode mines, he was a carpenter and builder by trade who had come to Alaska prior to the Klondike Gold Rush.
Beginnings
In 1880, prospectors Joseph 'Joe' Juneau and Richard Harris discovered gold in Silver Bow Basin. This brought waves of prospectors to the region, including John Treadwell, whose first move was to purchase a lode claim on Douglas Island from Pierre Joseph Erussard ("French Pete") on September 13, 1881.
Treadwell formed a partnership in Sept. 1881 with Erussard de Ville, D.P. Mitchell and Dave Martin under the name of The San Francisco Company. For unknown reasons he later backed out of this, and in early December 1881 he devoted his attention solely to the Douglas Island property. He then went on to buy two claims neighboring his property from D. W. Clark. Treadwell extracted twenty two samples from his three claims which he sent to San Francisco, California for a mill test, yielding encouraging results.
On December 27, 1881, Treadwell organized the Alaska Mill & Mining Company and began operations at the Treadwell Dike. Shortly after this, five men from California bought over $10,000 worth of stock in the business. These men were James Freeborn (1828 - June 21, 1894), San Francisco banker and mining magnate John Douglas Fry (July 1, 1819 - February 3, 1901), Horace Lewis Hill (1840 - November 6, 1912), Howard Hill Shinn (born April 4, 1857) and E. M. With these men funding him, Treadwell began running a tunnel and discovered that much of the vein he was mining was not on his property. Because word of his strike had not yet gotten out he was able to buy many of the adjoining claims for very little money, after which he returned to San Francisco to secure more backing for a much larger mill. His financial benefactors agreed to invest more and the major mining operation had begun.
By 1882, a 5-stamp mill was operating. In 1887, a 120-stamp mill was erected, which was doubled in size the next year. Between 1883 and 1896, three more mills were added to the Treadwell Complex. These served the Mexican, Seven Hundred Foot, and Ready Bullion mines. A second mill, with 300 stamps, was added to the Treadwell Mine in 1899.In 1889, Treadwell sold his stake in the company for $1.5 million (~$ in ) and returned to California.
Geology
The geology on Douglas Island consists of a belt of volcanic greenstones next to Stephens Passage, which alternate with slate before the transitioning into a belt of slate next to the Gastineau Channel. The slate band includes many dikes of diorite. "Secondarily fractured and mineralized diorite dikes constitute the ore bodies in the Treadwell group of mines on Douglas Island." Gold-bearing sulfide minerals impregnate the dikes, principally pyrite.
Operation
At the height of the operation there were five mills with over 960 stamps in continuous operation, closing down only on Christmas and Independence Day. These mills were fed by four mines known as the Treadwell, 700-Foot, Mexican and Ready Bullion. At this time the mine employed over 2,000 people and was the largest hard rock mine in the world. The gold was 55% free milling and 45% embedded in pyrite, which was extracted using chlorination, smelting, and cyanidation. Power to the complex was supplied by a coal-fired power plant (later switching to oil and two hydroelectric dams).
Some of the shafts extended as much as below the surface.
In 1914, many Serbian and Greek miners at Treadwell, who made up the bulk of the miners, left to fight for their home countries in World War I.
The Treadwell had its own baseball field and team that competed with four other teams from Alaska and Yukon. There was also a natatorium, which housed a swimming pool, as well as basketball courts.