Little River Canyon National Preserve is a United States National Preserve located on top of Lookout Mountain near Fort Payne, Alabama, and DeSoto State Park. Created by an Act of Congress in 1992, the 15,288-acre (6,187 ha) preserve protects what is sometimes said to be the nation's longest mountaintop river, the Little River. The canyon was historically called "May's Gulf", "gulf" being a common term throughout the Cumberland Plateau for this sort of feature. Prior to being assigned to the National Park Service, the canyon area formed the southmost unit of Alabama's DeSoto State Park.