Main Fork

Managing agency

Arapaho-Roosevelt NF — Boulder RD

Main Fork is a 6.0-mile loop trail located in Colorado near Boulder Ranger District within Arapaho-Roosevelt National Forest. The route features 1,615 feet of elevation gain, making it a moderately challenging hike suitable for those with some trail experience. The loop format allows hikers to experience varied terrain and scenery throughout the route without retracing their steps. The elevation gain is distributed across the trail, providing opportunities for both climbing and descent as you complete the circuit. Arapaho-Roosevelt National Forest offers the typical high country environment of the Colorado Front Range, including forested sections and open areas with mountain views. The Boulder Ranger District manages this trail and maintains it as part of the national forest's trail system. This hike works well as a half-day or full-day adventure depending on your pace and desired time in nature. The loop configuration makes it popular with hikers who prefer varied routes over out-and-back trails.