Mammoth Lakes lies on the edge of the Long Valley Caldera. The area around the town is geologically active, with hot springs and rhyolite domes that are less than 1000 years old.
Visitors can take State Route 203 from the town of Mammoth Lakes to the Mammoth Mountain Ski Area, over Minaret Summit, then down to Devils Postpile National Monument, with access to the Ansel Adams Wilderness.
The area has natural hot springs which are sometimes used after skiing. Other features include lakes, a soda springs, and an obsidian dome. Mammoth Lakes is north of the Owens Valley, a scenic area with extensive hiking opportunities.