Green River (Illinois) Green River (Illinois) The Green River is an tributary of the Rock River in northwestern Illinois in the United States. Via the Rock, it is part of the Mississippi River watershed. Much of the Green's course has been straightened and channelized. The Green rises in northern Lee County and flows initially southwestward through Lee, Whiteside and Bureau Counties, passing the town of Amboy. It turns westward in Bureau County and flows into Henry County, where it roughly parallels the Hennepin Canal and passes the towns of Colona and Green Rock. It joins the Rock River just west of Green Rock,
Big Black River (Mississippi) northern border of Claiborne County. The Big Black River and most of its tributaries are silt-filled. The rivers carry large amounts of suspended sediment, resulting mostly from agricultural runoff. These tributaries are slow-flowing muddy streams. However, some are swift-flowing with sandy bottoms. The Battle of Big Black River Bridge, fought during the Battle of Vicksburg, was part of the Vicksburg Campaign in the American Civil War. The size of the Big Black River Basin drainage area is . Its elevation varies from 50 to 650 feet (14 to 198 meters) above sea level. It is long and averages 22 to