The Santa Fe was a pioneer in intermodal freight transport; at one time or another it operated an airline, the short-lived Santa Fe Skyway, and a tugboat fleet. Its bus line extended passenger transportation to areas not accessible by rail, and ferryboats on the San Francisco Bay allowed travelers to complete their westward journeys to the Pacific Ocean. The ATSF was the subject of a popular song, Harry Warren and Johnny Mercer's "On the Atchison, Topeka and the Santa Fe", written for the film "The Harvey Girls" (1946).