Also called the Twin Lakes Trail, this is five miles (one way) of singletrack connecting Twin Lakes campground and the summit of Mammoth Mountain. Hikers use it from either of the two trailheads, or they use the local shuttle system to connect it as a loop. Hiking this trail provides several hours of invigorating trekking and some of Mammoth’s most exciting viewpoints. The Bottomless Pit refers to a natural rock bridge formation on what is known to skiers as Mammoth Mountain’s “back side,” or “hole in the wall.” Mountain bikers may be encountered on some stretches. To extend the hike, link up with more trails that descend from Mammoth Mountain’s summit.