Environmental Protection

In Beaver World

My First Summer in the Sierra (With Original Drawings & Photographs)

The Rocky Mountain Wonderland

A Pictorial Guide to Mesa Verde National Park

The Arctic Prairies : a Canoe-Journey of 2,000 Miles in Search of the Caribou

Jane Goodall: 50 Years at Gombe

A Rough Ride to the Future

Thornton Burgess: Collected Works

Morag the Seal

How to Camp Out

Sketches in Duneland

Adventure Travel Unleashed

The New 50 Simple Things Kids Can Do to Save the Earth

The Silent Places

Bears I Have Met—and Others

A Bird-Lover in the West

Mammals of the San Gabriel Mountains of California

Tree Magic

Gifts of an Eagle

Wild and Wonderful