Cadillac Desert is about land development and water policy in the western United States. Subtitled The American West and its Disappearing Water, it gives the history of the Bureau of Reclamation and U.S. Army Corps of Engineers, and their struggle to remake the American West. The book's main conclusion is that development-driven policies, formed when settling the West was the country's main concern, are having serious long-term negative effects on the environment and water quantity.