Yellowstone National Park is one of the world's truly extraordinary places. Its landscape, dominated by a great volcanic caldera and sculpted over millennia by water and glacial ice, is host to a dramatically complex flora and fauna. But there is more to Yellowstone's wonders than meets the eye. A nearly unexplored world awaits the curious in the park's streams and lakes, wetlands and beaver ponds, hot springs and geysers. This is the world of microbes--the bacteria, algae, diatoms, and other microscopic organisms that live at the very foundation of the Yellowstone ecosystem. This book takes readers on a spectacular and colorful tour of Yellowstone's microbial flora and fauna. Photographed using state-of-art technology, each microbe pictured in the book is presented together with photographs of the environment in which the organism is found. Readers will discover the amazing heat-tolerant bacteria that color many of the park's scalding hot springs, the microbes that allow a bison to digest grass, algae that thrive in acid, and microbial mats in every color of the rainbow. An eye-opener for adults and fascinating fun for kids, Yellowstone under the Microscope is a unique approach to the natural history of America's greatest national park.