North Boundary Trail is a hiking and horse trail in Larimer County, Colorado. It is within Comanche Peak Wilderness Area and Rocky Mountain National Park. It is 5.8 miles long and begins at 7,931 feet altitude. Traveling the entire trail is 11.7 miles with a total elevation gain of 4,395 feet. The Sylvanmere 2 and Sylvanmere 1 camp sites and the ranger cabin alpine hut can be seen along the trail. There are also parkings and an information guidepost along the trail.