The Everglades is commonly described as a swamp, but it is more accurately a slow-moving river roughly 60 miles wide and only inches deep, flowing from Lake Okeechobee to Florida Bay. This 18,000-square-mile system is the only place on Earth where wild alligators and crocodiles share the same water, with about 200,000 alligators in the freshwater marshes and roughly 2,000 crocodiles along the salt…