WordNet sense 1 (a river in Siberia that flows northwest to become a tributary of the Yenisei River):

Stony Tunguska

WordNet sense 2 (a river that arises north of Lake Baikal and flows north and west to the Yenisei River):

Lower Tunguska

WordNet sense 3 (a river in southeastern Siberia that flows northwest from Lake Baikal to become a tributary of the Yenisei River):

Angara, Angara River, Upper Tunguska