Jack Dykinga / Virgin river flowing through Zion Canyon Narrows, with reflections of afternoon sun, Zion National Park, Utah, USA

Jack Dykinga / Virgin river flowing through Zion Canyon Narrows, with reflections of afternoon sun, Zion National Park, Utah, USA

Konrad Wothe / Pechora River valley hills covered with virgin forest, Pechora-Ilych Biosphere Reserve, Ural Mountains, Russia

Tim Fitzharris / North Fork Virgin River, Zion National Park, Utah

Tim Fitzharris / Virgin River flowing through canyon in autumn, Zion National Park, Utah

Tim Fitzharris / Bridge Mountain and the north fork of the Virgin River, Zion National Park, Utah

Konstantin Mikhailov / Aerial view of river Birkin, right tributary of Ussuri River, with virgin riparian forest, North Ussuriland, Primorsky, Siberia, far east Russia

Konstantin Mikhailov / Aerial view of River Bikin, right tributary of Ussuri River, with virgin riparian forest, N Ussuriland, SE Siberia, far east Russia

Tim Fitzharris / Mt Spry at 5,823 foot elevation with the Virgin River surrounded by Cottonwood trees, Zion National Park, Utah

Tim Fitzharris / Mt Spry at 5,823 foot elevation with the Virgin River surrounded by Cottonwood trees, Zion National Park, Utah

Tim Fitzharris / North Fork of the Virgin River flanked by Cottonwood (Populus sp) trees, Zion National Park, Utah

Gerry Ellis / Traditional slash and burn clearcut in virgin lowland tropical rainforest east of Aird River Delta, Kikori Basin, Papua New Guinea

Gerry Ellis / New logging road in virgin lowland tropical rainforest, east of Aird River Delta, Kikori Basin, Papua New Guinea