This impressive stone and brick edifice first housed the offices of the Hardison and Stewart Oil Company and the Mission Transfer Company, a refining and marketing business. In October 1890, the Hardison and Stewart Oil Company, the Sespe Oil Company, and the Torrey Canon Oil Company joined forces to form the Union Oil Company. The incorporation papers were signed in the second floor offices.

The Union Oil Company building is the only commercial Queen Anne style structure in Ventura County that remains from the 1890s with its integrity intact.

Source: Adapted from the NRHP nomination submitted in 1986.

Union Oil Company is also California Historical Landmark 996.

When we photographed the building it housed the California Oil Museum.