Kenneth and William Willmarth were brothers who kept a studio in Omaha, near the headquarters of the Union Pacific, which naturally was one of their biggest clients. They were the only artists I know of to contribute two posters to the series, and it is not surprising that one of them represented the Pacific Northwest. Seeking to boost winter tourist travel, the Union Pacific Railroad opened Sun Valley, the nation's first destination winter resort, in 1936. Many of the Sun Valley posters were done by the Willmarths. William was a watercolorist, while Kenneth specialized in oils.