The Casa Diablo Hot Springs site is located on the southwestern edge of the resurgent dome along a major fault system. The fault forms the east side of the down-dropped block that transects the resurgent dome. This down-dropped block is called the medial graben. Three binary-cycle generators built here in 1985 and 1990 produce about 45 megawatts of electricity. Wells, each about 200 m deep, supply the powerplants with 170^o water. Heat exchangers transfer the thermal energy from the water to isobutane, which vaporizes and drives turbine generators.

Hot Creek is the lower reach of Mammoth Creek where several vigorous hot springs discharge hot water to the surface. The boiling pools along the creek (93^o C at this elevation), commonly change in vigor and location in response to local earthquakes and the seasonal rise and fall of the water level in the creek. The largest and hottest springs are located at the intersection of Hot Creek and two faults that are about 1 km apart. Some of these hot springs are hot enough to cause severe burns or even death. Hot-spring formations and ecosystems are very fragile. These areas should always be approached with respect and extreme caution.