An airboat loaded with passengers traverses a riverway through a marsh at the Everglades Safari Park, a tourist attraction in the Everglades, an ecosystem in South Florida that is unlike any other in the world. It is a unique mixture of estuarine waters, mangroves, freshwater marshes, cypress swamps, flat pine forests, and hardwood “hammocks” (rarely flooded high spots) among vast sawgrass plains. Photo by Carol Highsmith, 2020.