A Global Treasure nestled in the heart of the San Francisco Bay Area, San Bruno Mountain is one of the world's rare biodiversity hotspots. Bathed in fog and wind and preserved from destruction by the fierce work of local conservationists, this mountain offers visitors a glimpse of what San Francisco looked like before colonization. In this one-of-a-kind field guide, two of those conservationists, Doug Allshouse and David L. Nelson, offer a comprehensive yet accessible account of the mountain's flora-detailing 536 plant species-as well as the birds, butterflies, and reptiles that make their home in this diverse habitat at San Francisco's southern edge. With a plentitude of photographs to aid identification, this easy-to-navigate field guide belongs in the backpack of every curious visitor. Drawing on years of research and activism, the authors also delve into the dynamic changes to this mountain ecosystem-including its climate-and the political history of the preserve. Even yearslong locals and seasoned San Bruno hikers will discover revelations about the critical importance of this wild place. Book jacket.