When the United States entered World War I, the Coopers left England and returned to Montana. 16-year-old Frank helped out on the family ranch after brother Arthur enlisted in the Army. "Getting up at 5 a.m. and shoveling manure at forty below ain't romantic," Cooper said later, "but Dad was a true Westerner - and I take after him."
Frank also found he had a flair for drawing cartoons and caricatures, and while attending Grinnell College in Iowa he filled the school newspaper with his artwork.
During the summer of 1920 Frank was in a serious car crash that left him with a fractured hip. During his convalescence on the Cooper ranch, doctors suggested a rather unusual therapy - horseback riding. Young Coop soon became an expert (if pain-ridden) horseman.
In 1924 Charles Cooper resigned from the Supreme Court bench and he and Alice moved to Los Angeles to administer the estate of a cousin.
Broke and somewhat at loose ends, Frank joined his parents in L.A. on Thanksgiving Day, 1924. He hoped to pursue a career as a political cartoonist, but none of the local newspapers were impressed enough with his artistic abilities to give him a job.
Soon Frank was looking for any job he could get. After a stint as a photographer's assistant and then as a curtain salesman (!), Frank happened to meet up with two boyhood friends from Montana. He was intrigued by what they told him about their own jobs - stunt riding as cowboy extras at a movie studio. "In rodeo you're paid to stay on a horse," they said to Frank. "In films, it's for falling off."