Kaskaskia River an alternative name for the Kaskaskia that persists in place names along the river, including Okawville, and in a major tributary, the West Okaw River. The Kaskaskia rises in east central Illinois in several farm ditches along the west side of Champaign. The headwaters of the river is just north of Interstate 74, where it is marked with a sign. The river flows south across rural Champaign and Douglas counties, then southwest across southern Illinois, past Vandalia. It joins the Mississippi from the north approximately northwest of Chester and south-southeast of St. Louis, Missouri. The watershed of the river encompasses
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.