Big Muddy River Wisconsinan-era lake. This is why the Big Muddy tends to be so muddy. The Big Muddy joins the Mississippi River in Jackson County near the La Rue-Pine Hills Ecological Area and less than south of Grand Tower Island. The Pine Hills are bluffs overlooking the Big Muddy as it flows through La Rue swamp. During the melting of the Wisconsinan glacier, the Mississippi River flood plain was filled with rushing meltwater in summer. During the winter the flow of meltwater was cut off, and the floodplain was a wide stretch of exposed mud. Winter winds created dust storms that covered
Muddy River (Washington) gauge. Muddy River (Washington) The Muddy River is a stream, about long, southeast of Mount St. Helens in the U.S. state of Washington. The Muddy River flows south–southeast and joins the Lewis River just above the Swift Reservoir. The Lewis River flows west and is a tributary to the Columbia River. The east flank of Mount St. Helens is within the watershed of Muddy Creek. During the 1980 eruption of Mount St. Helens, lahars (volcanically-induced mud and debris flows) swept through its channel. About of stream channels around the volcano were affected by lahars. The United States Forest Service maintains