Black and white photograph of the Riverside Geyser in eruption, Yellowstone National Park. A group of people are standing and watching the geyser erupt. Taken by Robert Merrill looking east.

Black and white photograph of the Riverside Geyser in eruption, Yellowstone National Park. Taken by Robert Merrill looking southeast.

Castle Geyser in eruption at Yellowstone National Park, Wyoming.

Geyser cone at Yellowstone National Park, Wyoming.

Geyser cones at Yellowstone National Park, Wyoming.

Small geyser cone at Yellowstone National Park, Wyoming.

Yellowstone National Park is located primarily in Wyoming, but extends into parts of Montana and Idaho. Established as a National Park on March 1, 1872, it was the first national park in the world. It is known for its large variety of wildlife and…

Yellowstone National Park is located primarily in Wyoming, but extends into parts of Montana and Idaho. Established as a National Park on March 1, 1872, it was the first national park in the world. It is known for its large variety of wildlife and…