Big Muddy River Big Muddy River The Big Muddy River is a river in southern Illinois. It joins the Mississippi River just south of Grand Tower. The Big Muddy has been dammed near Benton, forming Rend Lake. The Big Muddy has a mud bottom for most of its length. The Big Muddy drains a watershed. In 1995, water quality was assessed as "fair" to "good". Pollution sources include agricultural practices, mining and municipalities. The watershed of the Big Muddy was covered by the Illinoian Glacier about 300,000 to 132,000 years before present. The Big Muddy basin formed after the retreat of that glacier.
Muddy River (Nevada) the Meadow Valley Wash, forming the principal drainage system for southeastern Nevada. The Moapa Valley area is home to a wide variety of rare and endangered species, including fish, invertebrates, birds, and plants. Three endangered fish inhabit the area: the Moapa dace ("Moapa coriacea"), the Virgin River chub ("Gila seminuda"), and the White River springfish ("Crenichthys baileyi moapae"). These species can be found throughout the various springs, called the Muddy Springs, that feed the Muddy River. The U.S. Fish and Wildlife Service has created the Moapa National Wildlife Refuge at the Warm Springs Natural Area, as part of the Desert