From Main Lodge, the Mammoth Mountain Trail threads its way up along the western flank of the dormant volcano that dominates the area. Above Reds Lake, the forest begins to thin toward treeline, affording ever-more-sweeping vistas across Reds Meadow Valley and the Ansel Adams Wilderness to the Ritter Range, the Minarets and down the San Joaquin drainage to Balloon Dome and the Central Valley beyond. The gondola building on the summit, at 11,053 feet, houses an interpretive center with information on geology, earthquakes, volcanoes, weather and the names of prominent peaks and mountaineers.