The river running through the Canyon de Chelly in Arizona.

The river running through the Canyon de Chelly in Arizona.

Black and white photograph of the Grand Canyon of the Yellowstone River. Taken by Robert Merrill from Grand View.

Black and white photograph in portrait orientation of the Grand Canyon of the Yellowstone River, Yellowstone National Park. Taken by Robert Merrill looking north.

Colorado River below Shoshone.

Colorado River near Sulphur Springs.

Colorado River North of Shoshone power plant.

Black and white photograph of Lower Falls, Yellowstone National Park. Taken by Robert Merrill, looking down from brink.

Black and white photograph in portrait orientation of the Grand Canyon of the Yellowstone River, Yellowstone National Park. Taken by Robert Merrill, looking east below Grand View.

Black and white photograph in portrait orientation of the Grand Canyon of the Yellowstone River, Yellowstone National Park. Taken by Robert Merrill, looking south from Inspiration Point.

Shawnee paddleboat and showboat on the Kentucky River.

D.J. Angus and friends aboard the Shawnee on the Kentucky River at Lockport, Kentucky.