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
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