Environmental Protection

Pets Gone Green

The Falls of Niagara and Other Famous Cataracts

From North Pole to Equator: Studies of Wild Life and Scenes in Many Lands

Trails and Tramps in Alaska and Newfoundland

Glacier National Park

Trees of Indiana

A Traveller in Little Things

Letters from Australia

Hampshire Days

Our National Forests

Wild Animals of North America

Outdoor pastimes of an American hunter

The Fight for Conservation

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

The Impossible Five