Fourmile Canyon in western Boulder County, Colorado, was carved by Fourmile Creek as it descends from Niwot Mountain through small mountain communities to Boulder Creek. Its history is closely linked to Colorado’s mining frontier: gold found here in 1859 drew early settlers, and tellurium discovered in 1872 renewed local mining activity. The canyon also became a vital route for transportation, carrying an early narrow-gauge railroad to mountain mines and settlements and later serving travelers on the Switzerland Trail. In 2010, it was devastated by one of Colorado’s most destructive wildfires, which burned thousands of acres, forced evacuations, and destroyed 168 homes.