This phrase refers to a specific type of publication: a book dedicated to showcasing the national parks of the United States. It commonly features photography, descriptions, maps, and other information relevant to exploring the parks. An example would be a guidebook used for planning a road trip through several of these protected areas.
Publications of this nature serve as valuable resources for both potential and seasoned travelers. They provide inspiration, practical advice regarding trails, accommodations, and permits, and contribute to a deeper understanding of the ecological and historical significance of these natural landscapes. The popularity of such books reflects a growing interest in outdoor recreation and conservation efforts.