Casa Diablo Hot Springs, California

Casa Diablo Hot Springs is situated within the Long Valley Caldera at approximately 7,300 feet (2,200 meters) elevation and features natural geothermal activity near Mammoth Lakes in eastern California. The landscape is defined by mountainous terrain and hot springs fed by underground geothermal resources.

The site served as a crucial supply station from 1878 to 1881 along the Bishop Creek-Bodie route, supporting multiple mining camps with goods and mail. This role as a distribution point was vital for the rapidly expanding mining communities of the region.

The area held significance for Indigenous peoples who extracted obsidian and fashioned tools that were distributed through extensive trade networks.

The location is accessible via US Route 395 at its intersection with California State Route 203, which connects to the Mammoth Lakes resort area. Visitors should account for the high elevation and mountain conditions, which can affect travel plans especially during winter weather.

Since 1983, the Mammoth Geothermal Complex has been converting natural geothermal resources into electricity through a power plant at the location. This makes it a working example of how the earth's heat can be harnessed for energy production.