Environmental Protection

El Morro Trails: El Morro National Monument, New Mexico

Carlsbad Caverns National Park, New Mexico

Integrated Environmental Footprint Index (IPAI)

Runaway Planet

Fresh Fields

The Spell of the Rockies

The Amateur Poacher

Underground Treasures: How and Where to Find Them

Burton Island State Park: Guide to the Interpretive Nature Trail and Hiking Trail

The Geology of Groton State Forest

The Migration of North American Birds

Krag and Johnny Bear

Wild Earth

The book of earth

Bee-Keeping

The Strangest Things in the World: A Book About Extraordinary Manifestations of Nature

Forest, Lake and Prairie

The apiary; or, bees, bee-hives, and bee culture

Wilderness Honey

The Wisdom of Albert Schweitzer