These two books were a pleasure to read. They tackle the history of ideas about regions deemed “marginal,” and the ideas and practices that have kept them so. Sayre and Davis deal, respectively, with misperceptions held about the marginal and arid U.S. West, and global arid lands (with a focus on the Sahara and its fringes). Having lived and worked in southern Arizona, central to Sayre's book, and in the West African Sahel, featured in Davis's work, I can see links between the two volumes, although they target different audiences. They both revolve around the consequences of misconstruing the nature of environments and the actions of peoples in arid lands, power-laden scientific assumptions, thwarted development aspirations, and human responses to aridity.