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 (Nevada) to the Colorado River and followed it westward. In 1844, the expedition of John C. Frémont discovered a cutoff route that avoided the Colorado River, following a route between Resting Springs in California, and the Virgin River Valley that passed through Las Vegas Springs and crossed the Muddy River near modern Glendale. Mormon pioneers blazed a wagon road from Salt Lake City to Los Angeles along this pack trail in 1847, followed by Forty-niners attempting avoid the winter snows of the Sierra Nevada Mountains, and wagon trains of Mormon colonists on their way to settle in San Bernardino in 1852.