Tower Falls from above, Yellowstone National Park.

Falls of the Gibbon, Yellowstone National Park.

Paint Pot, Lower Geyser Basin, Yellowstone National Park.

Formation near Mammoth Springs, Yellowstone National Park.

Summit of the Hot Springs, Yellowstone National Park.

McCartney's Cave, near Mammoth Springs, Yellowstone National Park.

Formation at Mammoth Hot Springs, Yellowstone National Park.

Gardner Canyon and Valley, Yellowstone National Park.

Grand Canyon of the Yellowstone, Yellowstone National Park.

Grand Canyon of the Yellowstone, Yellowstone National Park.

Grand Canyon of the Yellowstone, Yellowstone National Park.

Grand Canyon of the Yellowstone, Yellowstone National Park.

Grand Canyon of the Yellowstone, Yellowstone National Park.

Grand Canyon of the Yellowstone, Yellowstone National Park.

Great Falls of the Yellowstone, 360 feet, Yellowstone National Park.

Great Falls of the Yellowstone, 360 feet, Yellowstone National Park.

Sulphur Mountain and Valley, Yellowstone National Park.

A Mud Geyser Formation.

Specimen Lake, Upper Basin.

A Glimpse of the Geyser Basin, Yellowstone National Park.

Grand Geyser Cone and safety valve, Yellowstone National Park.

Grand Geyser Cone and safety valve, Yellowstone National Park.

Gibbon Falls, Gibbon River, Yellowstone National Park.

Devil's Thumb, Soda Deposit, Yellowstone National Park.

Petrified Tree.

Great Falls, 360 feet.

Rapids above the Upper Falls.

Hayden Valley.

Hot Spring Cone, Yellowstone Lake.

Glimpse of the Tetons.