An everglade might be defined most easily as a swampy tract covered with tall grass and dotted with occasional trees. In practice, however, the word almost always refers to the grand marsh of southern Florida, which is so flat that a broad sheet of water flows slowly across it on the way to the sea—a river with a valley so shallow it is measured in inches. The system is so finely balanced that minute variations in elevation can lead to dramatic changes in flora and fauna. The etymology of everglade is obscure, but “ever” may have been used to mean “interminable.” If so, it was a misnomer, for changes in land use and irrigation north of the Everglades have altered the flow of water and driven the area’s unique plants, animals, and processes to the point of extinction. As the twenty-first century begins, it is the site of the largest attempt at ecosystem restoration any place on the face of the globe, an expensive and desperate attempt to keep the concept of everglade alive.

Bill McKibben