The Delta River is an 80-mile (130 km) tributary of the Tanana River in the U.S. state of Alaska. Its name in the Ahtna language is Saas Na’ . Fed by the Tangle Lakes of the Alaska Range, the river flows north to meet the larger river near Big Delta.In 1980, 62 miles (100 km) of waterways in the Delta River basin, including all of the Tangle Lakes and the main stem to within 0.5 miles (0.8 km) of Black Rapids became part of the National Wild and Scenic Rivers System.