This is the first comprehensive look at America's national park system, an insider's tour covering the system and the National Park Service, the agency responsible for its care. Dwight F. Rettie, former chief of the NPS policy development office, is uniquely qualified to address the state--the problems and the possibilities--of the system, which is comprised of millions of acres of land in more than 350 areas around the nation, including historic sites, battlefields, and recreation areas.      Rettie agrees, as many critics have claimed, that the system is in disarray; he proposes in detail stronger management operations, clearer and more stringent measures of personnel performance, and training of park rangers to help them become professionals knowledgeable about the scientific management and protection of resources.      For a concerned public as well as for policy-makers and students of government, this comprehensive analysis and outline may provide hope--and a future--for the invaluable legacy that is our national park system.