West of South Tahoe in the Eldorado National Forest, the Loon Lake South Shore Trail (aka Rubicon Hiking Trail) is a 6 mile mountain biking route. This is a very scenic and very remote lake. The trail is shared by hikers, bikers and horseback riders.
Also known as the Rubicon Hiking Trail, the Loon Lake Wilderness Trailhead is located at the Loon Lake Campground off of Ice House Road. This trail follows the south shore of the lake for the first four miles with panoramic views of Loon Lake and the surrounding mountains. The trail then climbs over a small saddle and drops into Rockbound Valley. Beautiful views of Buck Island Lake, Rockbound Reservoir, Rockbound Valley and the peaks of Desolation Wilderness are visible from the trail as it drops into the Rubicon River Drainage. The Desolation Wilderness boundary is about 6.2 miles from the trailhead and a wilderness permit is required beyond that point.
Overall, Loon Lake Trail is the 101st most popular mountain bike trail of all 132 mountain biking rides in California.