His work as a stuntman caught the eye of director John Ford. Ford hired Johnson for stunt work in the 1948 film "Fort Apache", and as the riding double for Henry Fonda. During shooting, the horses pulling a wagon with three men in it stampeded. Johnson, who "happened to be settin' on a horse", stopped the runaway wagon and saved the men. When Ford promised that he would be rewarded, Johnson hoped it would be with another doubling job, or maybe a small speaking role. Instead he received a seven-year acting contract from Ford. Ford called Johnson into his office, handed him an envelope with a contract in it. Johnson started reading it and when he got to the fifth line and it said "$5,000 a week," he stopped reading, grabbed a pen, and signed it, and gave it back to Ford.