History 

The Fossil post office was established on February 28, 1876, on Thomas Benton Hoover's ranch along Hoover Creek. He named the place Fossil after finding fossils in a clay-like rock formation on his ranch. In 1881, Hoover and Thomas Watson opened a store near the confluence of Butte and Cottonwood creeks and moved the post office to the store. When the city was incorporated in 1891, Hoover became the first mayor.

After creating Wheeler County in 1899, the Oregon Legislature chose Fossil as the temporary county seat. A county-wide election held in 1900 to determine the permanent county seat yielded 436 votes for Fossil, 267 for Twickenham, and 82 for Spray

Winlock W. Steiwer and George S. Carpenter founded Steiwer & Carpenter Bank, the first bank in the city and the county.[10] By the early 20th century in addition to the bank, Fossil had a flour mill, a blacksmith shop, a drug store, a jewelry and optical store, a livery stable, and three stores with general merchandise. In the 1920s, William Jennings Bryan was one of the guest speakers at a Chautauqua meeting in Fossil. Later in the decade the John Day Valley Coal & Oil Company drilled an exploratory oil well within the city limits, but it was not successful *From Wikipedia