Big Muddy River Here the outline of the Wisconsinan Era lake bed is evident in what were the northern reaches of the ancient lake, where the lake bed was only a few hundred feet wide. The steep Illinoian hills are suddenly truncated where they meet the flat bottom of the Wisconsinan Era lake bed. Here the tributaries of the Big Muddy are tiny, intermittent streams, meandering though these narrow valleys at the headwaters. The Big Muddy basin contains a significant portion of the planet's coal reserves. Most of this is hidden under its deep mud. At a few places the river has eroded
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.