Big Muddy River Southern Illinois with "loess", fine grained, wind born deposits. At the edge of the floodplain, dunes, called "loess hills", formed. The Pine Hills are loess hills standing several hundred feet above the floodplain. Prior to the construction of Rend Lake, much of the ancient lake bed was swamp: a forested area that was covered by water through most of the winter, and during wet summers. When the Big Muddy flooded, the water covered the flat bottom of the ancient lake bed for miles either direction from the meandering channel. The upper reaches of the Big Muddy are near Dix, Illinois.
Muddy River (Nevada) By 1855 it had become a cold season freight route between Utah and Southern California that remained in use in Southern Nevada into the 20th century. Mormon settlers established several settlements in the Muddy River area in 1864, including the town of St. Thomas, which by 1938 was submerged under Lake Mead until recently. Some of the towns ruins can be still seen during low water levels. Some Paiutes fought to protect and reclaim their homeland. For a variety of reasons, including the harsh climate, unpredictable periods of drought, and a tax dispute with the State of Nevada, the Mormons