A recent bill passed in the U.S. Senate authorizes the National Park Service to acquire 590 acres of mangrove habitat and 10 acres of land in Tarpon Basin. The mangrove acreages sit mostly on two peninsulas that surround and form the two sides of Tarpon Basin, and abut the Intracoastal Waterway (Grouper and Dusenbury creeks).

The property was bought by The Nature Conservancy in 2003 and is critical to several endangered species. The Conservancy plans to give the property to the Park Service. Before the final go-ahead on the ENP expansion, the House of Representatives must also pass the bill which includes other portions of public land ranging to Alaska.