Cinder Cones in the Long Valley Area, California
Several small cinder cones are located on the floor and rim of Long Valley caldera. The youngest cones in the area include Red Cones 5 km (3.1 mi) south of Mammoth Mountain and Black Point on the north shore of Mono Lake. Geologists estimate that Red Cones may have erupted as recently as about 8,500 years ago and Black Point about 13,000 years ago. The other cones on the caldera floor and along the rim range in age from 228,000 to 64,000 years.