Buddy, a very young burro selected for his first trip into the Grand Canyon, is embarrassed when he sees that an old, clumsy pack frame is to be strapped to his back while his friend, Diego, has a handsome saddle placed on his back and is chosen to carry a person. Buddy feels his job is not an honorable or prestigious one. But after Diego injures his leg, medical supplies in Buddy's pack are used to help mend Diego's leg.