James Halfpenny has searched for dinosaur tracks in Colorado and Montana, tracked wildlife in Tanzania and Kenya, studied endangered species on China's Tibet-Qinghai plateau, and researched the polar bears of Hudson Bay and Greenland. Jim specializes in educational, environmentally-oriented programs about mammal behavior, tracking, and cold. Since 1961 he has taught outdoor and environmental education for a vast array of schools and organizations, including the Smithsonian, National Outdoor Leadership School, Outward Bound, the Appalachian Mountain Club, The Wilderness Society, National Wildlife Federation, Defenders of Wildlife, and National Audubon Society. He has trained rangers in tracking techniques at Yellowstone, Glacier, Grand Teton, and Rocky Mountain national parks. His research has also taken him to Antarctica, Japan, and all over North America. He is a fellow of the Explorer's Club and a Vietnam veteran. Halfpenny was featured, with Australian aborigines, Kalahari Bushmen, and Alaskan Inuits, in a documentary about the loss of native tracking skills shown on the Discovery Channel. He is a past field director and project coordinator for the University of Colorado's Institute of Arctic and Alpine Research. He is also the senior author of Scats and Tracks series, A Field Guide to Mammal Tracking in North America (Johson Books), Yellowstone Wolves in the Wild (Riverbend Press), Discovering Yellowstone Wolves: Watcher's Guide (A Naturalist's World), Winter: an Ecological Handbook (Johson Books) and Bare Feet, Wet Socks: Writing about Winter (edited with Ann Zwinger, Caldera Press). He lives just outside Yellowstone National Park in Gardiner, Montana.Todd Telander is a freelance natural science illustrator and wildlife artist. He studied biology and environmental studies at the University of California, Santa Cruz, where he became interested in illustration. His work appears in Falcon's America's 100 Most Wanted Birds, Birder's Dictionary, A Field Guide to Cows, and A Field Guide to Pigs as well as in museums, galleries, and private collections. Telander lives in Trinidad, California.