Settled in 1877, Bonanza was the first major settlement in the Yankee Fork area of Salmon River country in Central Idaho. By 1881, Bonanza had a population of over 600 residents, making it temporarily the largest settlement in the area. Bonanza's population would soon decline however, and nearby Custer would become the economic and social center of the Yankee Fork region.
Charles Franklin, originally from Bodie, California, had the idea of building a town among the rich placers of the Yankee Fork of the Salmon River. He began selling lots in his new town of Bonanaza in the summer of 1877, and eager miners were happy to purchase them at prices ranging from $40 to $300.
Miners in the area, excited about a bit of civilization in the remote mining area, took time out from mining to help build the new camp. The first buildings were constructed of logs with roofs of hand-hewn shakes. It wasn't long before a saloon was completed, and enthusiastic miners from all over the area descended on Bonanza to celebrate.
In 1881, Bonanza had a dentist, a tin shop, a watchmaker and the first newspaper in Custer County, The The Yankee Fork Herald, which was published from 1879 to 1882.The publication Land of the Yankee Fork Historical Area in Words and Pictures gives the following description of Bonanza: "Through the years, Bonanza retained its charm. It had no mine or noisy mill. Instead, there were gentle hills and three bridges across the Yankee Fork. The town had a croquet field, a baseball field, and a small race track. It was quiet and friendly with tree-lined streets and a water system, supplied from community wells, and a fire protection system."
Much of the Bonanza burned in an 1889 fire, resulting in many residents relocating to Custer. The 1890 population was listed as 136 residents.
Bonanaza was mostly abandoned by 1910 as the local mining industry became idle.
The Yankee Fork would see the construction of a gold dredge in 1939. The dredge operated until 1952 (with a two year shutdown during World War II) and recovered over eleven million dollars in gold.
Today only a few dilapidated buildings remain at the Bonanza town site. The Yankee Fork Gold Dredge rests just up the road and is open seasonally for tours.