Hartsel's operation became, according to the 1919 book The History of Colorado by Wilbur Fiske Stone, one of the largest and best-stocked cattle ranches of the state.On fifteen thousand acres, Hartsel grew oats, wheat, barley, rye, and hay. He developed the Hartsel hot springs, which served his own ranch with a two-mile long pipeline of hollow wooden logs. He built a sawmill, blacksmith shop, and a trading post to lay the groundwork for the town, established where the south and middle forks of the South Platte River converge.