Castle Geyser in Yellowstone's Upper Geyser Basin erupts from a 4-m-high, 12-m-wide sinter mound. Eruptions of Castle Geyser are typically sustained for an hour or more.

Copyrighted photo by Katia and Maurice Krafft, 1984.

Copyrighted image used with permission. All Rights Reserved. Contact photographer for any usage requests.

Yellowstone