Mix's last screen appearance was a 15-episode sound Mascot Pictures serial, "The Miracle Rider" (1935); he received $40,000 for the four weeks of filming. Outdoor action sequences for the production were filmed primarily on the Iverson Movie Ranch in Chatsworth, California, on the outskirts of Los Angeles. The site was known for its huge sandstone boulders, and one of them later became known as Tom Mix Rock when it was discovered it had been used in "The Miracle Rider". In one episode, Mix was filmed descending from the top of the rock, with boot holes carved into it to assist him in making the descent. The rock and the boot holes, although unmarked, is in the Garden of the Gods park in Chatsworth.