MSRMapCruncherOutputGUID MSRMapCruncherOutputGUIDVersionCBB As it winds from Minnesota to the Gulf of Mexico, the Mississippi River is in constant flux. Fast water carries sediment while slow water deposits it. Soft riverbanks are continuously eroded. Floods occasionally spread across the wide, shallow valley that flanks the river, and new channels are left behind when the water recedes. This history of change is recorded in the Geological Investigation of the Alluvial Valley of the Lower Mississippi River, published by the Army Corps of Engineers in 1944.