Laurel Hill Creek, the Casselman River's largest tributary, helps form the "Turkeyfoot" at Confluence, a nickname tied to the shape shown on George Washington's 1753 map after American Indians scouting for his diplomatic mission to Pittsburgh identified the area where Laurel Hill Creek and the Casselman River join the Youghiogheny River. The watershed drains 125 square miles along the eastern side of Laurel Ridge, and its main stem and tributaries are largely designated by the state as High Quality Coldwater Fisheries, with several classified as Exceptional Value. Because it had minimal coal mining and related abandoned mine drainage, it is one of the region's most pristine watersheds and a popular trout fishing destination in Southwestern Pennsylvania. In the Laurel Highlands, the watershed region includes Seven Springs and Hidden Valley Resorts, Forbes State Forest, and Laurel Hill, Kooser, and Laurel Ridge State Parks, while agriculture, forestry, recreation, and heritage tourism all support the local economy. Laurel Hill Creek is also a Class I-III whitewater river with changing and potentially life-threatening natural hazards, and after American Rivers named it one of America's 10 Most Endangered Rivers because of extensive water withdrawals, residents, agencies, water suppliers, and businesses began collaborating through a Critical Area Resource Plan to preserve sufficient water for the future.