The Castle Rock Loop is part of the Carson Range, which begins at Carson Pass and ends at the Truckee River. Unlike other ranges in the Lake Tahoe area, the Carson Range was not formed by glaciers. You can find both granite and volcanic rock in the area. This trail is also unique in that it is not well known, and it remains less crowded than more popular neighboring hikes. Note that to reach the lower ledge of Castle Rock, be prepared for some rock scrambling. The actual summit requires climbing.
This 3.1-mile hike follows the Tahoe Rim Trail for about a mile of gradual undulations before the junction with Castle Rock Trail. Turn left onto the trail and follow for another three-quarters of a mile until you reach a marker for Castle Rock Summit. From here you will ascend 300 feet to the base of the rock. There are a few paths to reach the lower ledge, all of which require some easy scrambling over exposed rock. This is a great spot for lunch and photos. If you are feeling brave, you can attempt the extra climb to the actual peak, which includes a few Class V moves. Once you are ready to leave, carefully climb back to the base, then follow the Castle Rock Trail back to the parking area, turning right at the same junction.