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 marauding Indians, boiling geysers and ferocious bears, but Uncle Bird promises her he’ll stay on safe routes, and he’ll teach Macon to shoot his father’s rifle. Macon becomes a sharpshooter while he and Uncle Bird travel 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 leads straight to a band of murderous horse thieves.