In the gift shop of South Carolina’s Congaree National Park, visitors can choose between two maps to help them explore the largest expanse of old-growth bottomland hardwood forest left in North America. In the first one, printed by the National Park Service, most of the detail is concentrated in the top left corner near the park’s headquarters: loops of hiking trails plotted in dotted lines, major waterways rendered in icy blue. The rest of the map—the park’s 22,000-acre backcountry—is depicted as a barren expanse of pale green, interrupted only by…
