Belle Fourche River near Devil’s Tower, Wyoming

The Belle Fourche River flows through a landscape of red rock formations and pine forests in eastern Wyoming, near Devil's Tower National Monument. This river is the longest "all-water" river in the United States, meaning it is a river that flows entirely within the U.S. and is not a tributary to any other river. The Belle Fourche River has historically been important for agriculture and ranching in the region, with irrigation projects utilizing its waters since the early 20th century. Today, the area surrounding the river, including the nearby national monument, is a popular destination for camping and outdoor activities.