Walt Coburn's father pioneered in Montana Territory, joined the Vigilantes who chased road agents, and eventually built up one of the biggest cow outfits in the young state. The Circle C Ranch spread over thirty thousand acres in northern Montana, near the town of Malta.

Walt is rather small for age fourteen - only 'stirrup high' to his pony Snowflake - when he works on the Circle C and learns a lot from the tough cowboys, and from his own scrapes and falls. His summer vacation from school increases in excitement when Kid Curry and other members of the Wild Bunch loom on the horizon. Stirrup High conveys all the know-how and atmosphere of roughing it on a ranch in 1903.