Chase Dekker / Red Fox (Vulpes vulpes) in winter, Grand Teton National Park, Wyoming

Chase Dekker / Great Gray Owl (Strix nebulosa), Grand Teton National Park, Wyoming

Daniel J. Cox / Gray Wolf (Canis lupus) pack on ridge in winter, Lamar Valley, Yellowstone National Park, Wyoming

Matthias Breiter / American Bison (Bison bison) herd grazing, Grand Teton National Park, Wyoming

Chase Dekker / Moose (Alces alces) bull, Grand Teton National Park, Wyoming

Jeff Foott / American Pika (Ochotona princeps), Bridger-Teton National Forest, Wyoming

Jeff Foott / American Pika (Ochotona princeps), Bridger-Teton National Forest, Wyoming

Jeff Foott / American Pika (Ochotona princeps) alarm calling, Bridger-Teton National Forest, Wyoming

Jeff Foott / American Pika (Ochotona princeps), Bridger-Teton National Forest, Wyoming

Jeff Foott / Trumpeter Swan (Cygnus buccinator) parents and cygnets, National Elk Refuge, Wyoming

Jeff Foott / American Pika (Ochotona princeps) carrying plants for hay pile, Bridger-Teton National Forest, Wyoming

Jeff Foott / American Pika (Ochotona princeps) carrying plants for hay pile, Bridger-Teton National Forest, Wyoming