Poudre Canyon is a glacier-carved valley along the upper Cache la Poudre River in northern Colorado, stretching about 40 miles from near the Continental Divide to the plains north of Bellvue. Shaped by glaciation and river erosion, it has been used for thousands of years by Utes, Arapahoe, and earlier Paleo-Indians. In the 19th century it saw trapping, limited mining, and unsuccessful railroad surveys, while a road through the narrows was built in the 1920s. Settlement has remained sparse, and the canyon is valued chiefly for recreation, though recent wildfires, especially in 2012 and 2020, have heavily affected the landscape.