river in northeastern India, rising in southern Bihar state. The Subarnarekha (meaning “Streak of Gold”) flows east through a copper-mining region and leaves the Chota Nagpur plateau by the Hundrugbagh waterfall. Continuing eastward, it flows across West Bengal state to enter the Bay of Bengal (Bengal, Bay of) after a 290-mile (470-km) course. The Kanchi and Karkari rivers are its chief tributaries.