The word biodiversity often conjures up visions of tropical rain forests, and for good reason. They contain more species than anywhere else in the world. But, as this lavishly illustrated and well written book attests there is a great deal of biodiversity in the U.S. In fact, U.S. is the richest country in terms of numbers of species for several groups inclulding freshwater mussels and crayfishes. The authors take us through the groups of plants and animals in the U.S. with a combination of natural history descriptions, photographs, maps, and when appropriate, data summaries. The maps are really noteworthy, because they add a great deal to the book both visually and in terms of understanding the patterns. The book is well worthy the cost just for the photos and maps. Later chapters address the patterns of rarity, threats, and protection strategies. In terms of style and content, it rests between David Wilcove's, The Condor's Shadow and Terrestrial Ecoregions of North America: A Conservation Assessment by Taylor Ricketts et al. Precious Heritage belongs on the bookshelves of everyone interested in and concerned about biodiversity in the U.S.