The Everglades is a unique wetland ecosystem in southern Florida, with 5,000 square miles of slow-flowing water supporting grasslands, thick forests and diverse groups of animal life. Often referred to as the 'River of Grass', the swampy Everglades create endless prairies of sawgrass that rise 3 to 10 feet above the surface of the water. The sawgrass is often so dense that travel is possible only through shallow natural water passages, hence the use of those famous flat-bottomed Florida airboats. The Everglades are known for birds like the roseate spoonbill, great blue heron and a variety of egrets. Marine life includes alligators, American crocodiles, soft shelled turtles and fish such as red teriera, large mouth bass, redfish, and catfish. Other wildlife in the Everglades National Park includes deer, the endangered Florida panther and over 28 different snakes.