Big Sandy River
a river forming the boundary between West Virginia and Kentucky, and flowing into the Ohio; having two confluent forks, Tug Fork, that rises in West Virginia, and West Fork, that rises in Kentucky. It is navigable for 100 miles of its lower course; flows through a timber and coal region.
BIG SIOUX (sû), a river of South Dakota that flows into the Missouri near Sioux City; it is 285 miles long.