This Forest Service “trail” is actually an old mining road which climbs 6.3 miles out to the beautiful Warren Lakes. While it’s possible to run the whole length of the road out and back, the final section is quite steep. Many runners choose to take on the most popular section, which is 1.5 miles from the parking area at the base of the trailhead up to the Smuggler Mountain Overlook. Past that, the trail gets steeper and more challenging. This Forest Service trail description is helpful.