Environmental Protection

Wild Apples

The Falls of Niagara and Other Famous Cataracts

Wild Animals of North America

The Fight for Conservation

Whitefoot the Wood Mouse

Lobo, Rag and Vixen

Ferdinand Vandiveer Hayden and the Founding of the Yellowstone National Park

God's Country: The Trail to Happiness

Our Common Land (and Other Short Essays)

The Land of Little Rain

Moths of the Limberlost: A Book About Limberlost Cabin

HENRY DAVID THOREAU – Ultimate Collection: 6 Books, 26 Essays & 60+ Poems, Including Translations. Biographies & Letters (Illustrated)

The Encantadas

Grand Teton [Wyoming] National Park

African Nature Notes and Reminiscences

Wild Animals at Home

Descriptions of Two Species of Frogs, Genus Ptychohyla

My First Summer in the Sierra (Illustrated Edition)

Birds in Town & Village

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