Hayden Valley

Mud Geyser in Yellowstone National Park, Wyoming, US

Black Dragon's Caldron and Sour Lake in Yellowstone National Park, Wyoming, US

A wooden bridge over a rocky stream, with steam rising from a geothermal vent nearby and trees on the hillside in the background.

Sizzling Basin and Churning Caldron in Yellowstone National Park, Wyoming, US

Mud Caldron in Yellowstone National Park, Wyoming, US