Big Muddy National Fish and Wildlife Refuge Clark was considerably different from today's river. The historic Missouri was a broad, slow-moving, shallow river with braided channels. These past river conditions created a haven for wildlife, which included vast floodplain forests of giant trees, marshes, and even wet prairies. Today's river is channelized. It is deeper and faster, and controlled by levees, dikes, and other containment structures. These controls make the river more navigable and the surrounding floodplain ideal for agriculture. The Big Muddy Refuge is allowing the Missouri River to be a river again, to enter its floodplain. This occurs during minor flood events. Management has created
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