Mud Volcano, steaming thermal spring in the back, Dragon's Mouth Spring, Yellowstone National Park, Wyoming, USA, North America

american america boggy deserted dragon's mouth spring empty famous place geothermal area geothermal power geothermal spring geothermal geothermic energy geothermic hot spring hot marsh area marshland marshy mud dome muddy mud volcanos mud volcano mud np national parks national park usa national park natural preserves natural preserve nature reserves nature reserve nobody no one no people north america place of interest protected area reserves reserve sanctury sights sight source springs spring steaming steam swamps swampy swamp thermal area thermal springs thermal spring tourist attractions tourist attraction travel photography travel uninhabited united states of america united states us american us america usa waters water vapor water wetlands wetland wyoming yellowstone national park