Amga, a river in Siberia, which rises in the Yablonnoy mountain range, flows in a N. N. E. direction nearly 460 m., and falls into the Aldan, the principal eastern affluent of the Lena. At its passage through the village of Amginsk, where it is bounded on each side by steep rocks upward of 30 feet in height, it attains a breadth of 3,000 feet.