Boiling Mudpot, Sulfur Works, Lassen Volcanic National Park, California

A boiling mudpot erupts at Sulphur Works in Lassen Volcanic National Park, California. Water from melting snow seeps into the ground above this mudpot, soaks through the soil and works down through cracks and fissures in the rock. Eventually, it touches hot rock and gasses in what used to be the main vent of Brokeoff Volcano, becomes superheated and returns to the surface as hot water or steam.