- The hike up to Mills Lake is a steady, uphill, 5.6 mile trek into the breathtaking Glacier Gorge trail system of Rocky Mountain National Park. You’ll be entranced by spectacular views of mountain ridges, rugged peaks, and the color of wildflowers along the trail. Glacier Gorge provides surprises at almost every turn. Explore the full Mills Lake hike profile below for trail map, driving directions, and all the details you need to enjoy this adventure in Rocky Mountain National Park.
