In this groundbreaking and meticulously field-tested guide, the rich variety of Sierra life--trees, wildflowers, ferns, fungi, lichens, fish, reptiles, amphibians, birds, mammals, and insects--comes alive. Easy-to-use features include: Intuitive organization, color tabs, and simple keys; Similar-looking species side by side; Over 2,800 full-color illustrations; Range maps of species that are otherwise difficult to distinguish; Index of common and scientific names; Lightweight and compact--ideal for backpacking. Impressively detailed and comprehensive, the guide includes: More than 1,700 species; Descriptions of behavior, adaptations, and interactions between species; Species and topics not found in most guides, including aquatic life, spiders and webs, plankton, plant galls, bark beetle galleries, animal tracks and evidence, seasonal star charts, weather patterns, and cloud formations.