[1] His most notable designs during this time in the Pacific Northwest included the Old Capitol Building in Olympia, and the courthouses in Spokane, Whatcom, and Port Townsend.
His work caught the attention of the Southern Pacific Railroad (SP), which had its headquarters in San Francisco.
He designed three of the SP's hospitals, in San Francisco,[3][4][5] El Paso, and Houston, as well as many of the railroad's industrial structures, such as electrical sub-stations and the Alameda Shops.
Although most of his work in San Francisco was done for the SP railroad, Patterson maintained his practice on behalf of other clients.
He also designed a large 4-story house for Jeremiah and Elizabeth Burke in Berkeley, California.