Sour Lake Mud Volcano Black Dragon's Cauldron Sour Lake Bull Bison Bull Bison Bison Mud Mud Pots Mud Volcano Grizzly Fumarole Sour Lake Black Dragon's Cauldron Dragon's Mouth Spring Sandhill Cranes Nez Perce Ford and Pelican Cone Yellowstone Lake Overlook Peak Yellowstone Lake Yellowstone Lake Sylvan Pass Sylvan Pass Sylvan Pass Mud Volcano Hot Spring Dragon's Mouth Spring Sizzling Basin Run-off Bull Bison Elk Great Blue Heron Hayden Valley Hayden Valley Hayden Valley Hayden Valley Lower Yellowstone Falls from Artist's Point Lower Yellowstone Falls Lower Yellowstone Falls Artist's Point Lower Yellowstone Falls Lower Yellowstone Falls from Uncle Tom's Trail Lower Yellowstone Falls Grand Canyon of the Yellowstone Grand Canyon of the Yellowstone Grand Canyon of the Yellowstone