National Park Service Maps
National Park Service maps are free and available either by mail or from any of the national park's visitor centers. These maps are revised and edited annually. They can also be viewed on computer in PDF format on the Park Service's website by clicking on the following link: NPS website
These maps are not designed for detail and cover an entire park at a time. This means that detail would be minimal though land feathures and cities show up very well. Elevation is given for most places though the map isn't topographic. On the back of each map is information that can be useful to hikers, campers and mountaineers about permits and regulations. Also on the back is information about flora and fauna. Photos are plentiful and should allow you to visualize what the park is like.