The Fountain Paint Pot is a mud pot located in Lower Geyser Basin in Yellowstone National Park.
The Fountain Paint Pot is named for the reds, yellows and browns of the mud in this area. The differing colors are derived from oxidation states of the iron in the mud. As with all hot springs, the heat in the caldera forces pressurized water up through the ground, which is expelled here. Also, rising gasses cause the bubbling action.
Wikipedia https://en.wikipedia.org/wiki/Fountain_Paint_Pot
Address Grand Loop Rd, 82190, United States
Coordinates 44°33'2.197" N -110°48'22.464" E