Fourteen-year-old Macon Josey must earn enough money so his widowed mother won’t have to give up his baby sister for adoption. He sees a chance when Uncle Bird Calfee offers him a job caring for art equipment on a trip to the brand new Yellowstone Park. Macon’s mother fears for her son’s safety, but Uncle Bird promises her he’ll stay on routes that avoid danger, and he’ll teach Macon to shoot his father’s rifle. Macon learns to be a sharpshooter while he and Uncle Bird travel meeting colorful characters and seeing hot springs, waterfalls, and canyons. This new skill becomes crucial after Uncle Bird falls into a geyser and Macon has to figure out how to get his scalded friend home. The only way is to head straight toward a band of murderous horse thieves.