He owned and operated the Treadwell gold mine through the Treadwell Mining Company. He was responsible for initiating low-grade gold mining in Alaska adopting most advanced operations on a big scale, which boosted the economy of the wilderness ares. His four mines formed the largest complex in the world at that time.
Treadwell"s mine complex "put Juneau on the map".
Treadwell worked as a miner in California and Nevada. In 1881, he worked as a carpenter on a house in California for John Fry, a well known banker.
When Fry heard about the rich gold exploring possibility around the Gastineau Channel on Douglas Island, near Alaska"s current capital of Juneau, he proposed Treadwell to inspect the area and find out the scope of prospecting there as Treadwell had a mining background. Initially, Treadwell met a French miner, Pierre Joseph Erussard, who gave very encouraging reports of the gold deposits in his claim.
As Erussard was short of funds to carry out further work, he decided to return to his country, and Treadwell gave Erussard $400 for the Paris lode claim.
On Treadwell"s return to California, he, Fry, and another friend established a mining company to work on Alaskan mine claims. The Alaska Mill and Mining Company was established in May 1882. Explorations on an experimental basis included a five-stamp mill.
The results proved profitable and the company expanded with a bigger sized 120-stamp mill in 1883 and another in 1887.
In the initial years, the Treadwell Complex had four mines (Treadwell, Ready Bullion, the Mexican and the Seven-Hundred-Foot)) and five mills. The gold yield was worth about United States$70 million.
In 1889, Treadwell sold his mining operations to the Alaska Gold Mining Company for a reported $1.5 million. Treadwell ventured into coal mining which turned out be a failure.
He owned and operated the Tesla Coal Mine, now situated in the Carnegie State Vehicular Recreation Area.
He died in New York on December 6, 1927 where he is buried.