Cave of Bones: A True Story of Discovery, Adventure, and Human Origins

Madam How and Lady Why

The Ends of the World: Volcanic Apocalypses, Lethal Oceans, and Our Quest to Understand Earth's Past Mass Extinctions

Rockhounding Colorado: A Guide to the State's Best Rockhounding Sites (Rockhounding Series)

Dinosaurs: The Textbook

Gem Trails of Oregon

Our Human Story

The Secret Lives Of Bats: My Adventures with the World's Most Misunderstood Mammals

Sea Glass Guide: The Ultimate Sea Glass Hunting Companion

National Audubon Society Field Guide to North American Fossils