The Thunder Loop can be ridden in either direction from the main trailhead for the Thunder trails. The west side of the loop follows the edge of Naturita Canyon and has more rocky terrain. The east side is more smooth with a little more flow.
Throughout the trail, you'll experience a mix of spruce and pine forests as well as open alpine meadows. No matter which direction you choose to ride, you'll end with a nice, downhill run back to the parking area.