Jeff Foott / Sunwapta Falls, Sunwapta River, Jasper National Park, Alberta, Canada

Jeff Foott / Sunwapta Falls, Sunwapta River, Jasper National Park, Alberta, Canada

Jeff Foott / Yosemite Falls and Merced River, Yosemite National Park, California

Juergen Freund / Wide angle shot of Barron Falls after a cyclone, showing increased flow of water, Wet Tropics World Heritage Area, Cape Tribulation, North Queensland, Australia. 2017.

Juergen Freund / Close-up of Barron Falls after a cyclone, showing increased flow of water, Wet Tropics World Heritage Area, Cape Tribulation, North Queensland, Australia. 2017.

Guy Edwardes / Cauldron Force, West Burton, Yorkshire Dales National Park, North Yorkshire, England, UK, June.

Tim Fitzharris / Conifers and Lower Yellowstone Falls, Yellowstone River, Grand Canyon of Yellowstone, Yellowstone National Park, Wyoming

Jeff Foott / Waterfall and river in canyon, Calf Creek Falls, Grand Staircase-Escalante National Monument, Utah

Jeff Foott / Trees in fall near Calf Creek Falls, Grand Staircase-Escalante National Monument, Utah

Kirkendall-Spring / Lower Yellowstone Falls on the Yellowstone River viewed from Artist Point, Yellowstone National Park, Wyoming, USA, June 2013.

Kirkendall-Spring / Lower Yellowstone Falls with rainbow, on the Yellowstone River viewed from Lookout Point Trail, Yellowstone National Park, Wyoming, USA, June 2013.

Kirkendall-Spring / Base of Lower Yellowstone Falls on the Yellowstone River in Yellowstone National Park, Wyoming, USA, July 2013.