Information / Sources, Mammoth Lakes
Off of the main highway that leads into Mammoth proper, there is a little side road by the Fish Hatchery. This little side road takes you to a hidden valley where a hot spring has evolved over the years. There are patches of really hot water and then, there are patches of really cold water that streams down from the Sierra Nevadas. The hot springs come from the hot magma underneather Mammoth Mountain. Mammoth is actually a volcanic mountain that is still somewhat active. There are no eruptions, but the volcanic activity is what creates this hot magma underground. Be careful though, because there are certain areas where the water will scorch you to death. There are signs for the areas that are too hot.