Biking--The 33-mile circuit of Crater Lake is one of the most popular road-bike trips in the state, despite the heavy car traffic. Although it would seem at first that this would be an easy trip, numerous ups and downs (especially on the east side of the lake) turn it into a demanding ride. Keep in mind that there are more hills on the east side, but there are also more views. An alternative is to do the 21-mile out and back ride from the Rim Village to the Cleetwood Cove Trailhead (and maybe add on a boat tour of the lake). There are no bike rentals available in the park, but Diamond Lake Resort rents them in the summer.