Devil's Postpile National Monument

The Devil's Postpile National Monument, located near Mammoth Mountain, is 13 miles west of Mammoth Lakes, CA. The monument contains 798 acres of wilderness and features two main attractions for tourists: Devil's Postpile and Rainbow Falls.

The postpile was created approximately 100,000 years ago when a lava flow erupted upstream and eventually ran into an obstruction creating a lava pool up to 400 feet deep. The lava formed hexagonal columns as it slowly cooled and contracted. Roughly 80,000 years later, a glacier passed through the same valley revealing the sides and tops of the columns.

Rainbow Falls, a 2.5-mile walk from the ranger station, is the highest waterfall on the San Joaquin River's middle fork. Spilling over 100 feet down into the below waters, many rainbows appear through the mist on sunny days.

The Devil's Postpile also serves as the starting point for several day hikes as well as backcountry trips. Several other summer and winter activities such as fishing, wildlife watching, mountain and road biking, horseback riding, snowshoeing and backcountry skiing are available.

Devil's Postpile is open 7 days a week, 24 hours a day during the operating season, typically mid-June through mid-October. The Ranger Station is open from 9-5 daily. Permits are required for all overnight trips.