Patricio Robles Gil / Bighorn sheep (Ovis canadensis) ram grazing in snow, Wind River Range, Wyoming, USA, January

Colin Monteath / Wind clouds over snow covered valley, Tasman Glacier, Hooker River, Liebig Range, Mount Cook National Park, New Zealand

Colin Monteath / Wind clouds over snow covered valley, Tasman Glacier, Hooker River, Liebig Range, Mount Cook National Park, New Zealand

Patricio Robles Gil / Two Bighorn sheep (Ovis canadensis) rams, one feeding, Wind River Range, Wyoming, USA, January

Patricio Robles Gil / Bighorn sheep (Ovis canadensis) ram running down a snow covered slope, Wind River Range, Wyoming, USA, January

Patricio Robles Gil / Bighorn sheep (Ovis canadensis) ram running down snow covered slope, Wind River Range, Wyoming, USA, January

Patricio Robles Gil / Bighorn sheep (Ovis canadensis) group during the rut, one pair mating, Wind River Range, Wyoming, USA, January

Patricio Robles Gil / Bighorn sheep (Ovis canadensis) group during the rut, large ram fighting a smaller ram, Wind River Range, Wyoming, USA, January

Patricio Robles Gil / Bighorn sheep (Ovis canadensis) group during the rut, large ram fighting a smaller ram, Wind River Range, Wyoming, USA, January

Jeff Vanuga / Rocky Mountain Bighorn Sheep {Ovis canadensis} male testing the air, flehmen behaviour, Whiskey Basin Sheep Range. Wind River Mts, near Dubois, Wyoming, USA, November

Kirkendall-Spring / Titcomb Lake at the foot of the Wind River Range, Rocky Mountains, Wyoming, USA

Kirkendall-Spring / Squaretop Mountain with the Green River in the foreground, Wind River Range, Bridger Wilderness, Wyoming, USA

Tim Fitzharris / Wind River Range and Ninepipe National Wildlife Refuge with extensive marshlands, Wyoming