Environmental Protection

The Underworld of Oregon Caves National Monument

Green WakeUp

The Book of Nature

Our Arctic province : Alaska and the Seal Islands

The Grizzly King

Carlsbad Caverns National Park, New Mexico

Global Warming

Master the Flame

Stories of Resilience

Clean Naturally

Wildebeest Realm, The Great Migrators

Gear Power

Descriptions of Two Species of Frogs, Genus Ptychohyla

The turtles, snakes, frogs and other reptiles and amphibians of New England and the north

Birds in Town & Village

Birds in Town & Village

Hunting the Grisly and Other Sketches

My First Summer in the Sierra (Illustrated Edition)

Colin Clout's Calendar: The Record of a Summer, April-October

Sanctuary: A Bird Masque