Green River (Illinois) in the Quad Cities metropolitan area. Green River (Illinois) The Green River is an tributary of the Rock River in northwestern Illinois in the United States. Via the Rock, it is part of the Mississippi River watershed. Much of the Green's course has been straightened and channelized. The Green rises in northern Lee County and flows initially southwestward through Lee, Whiteside and Bureau Counties, passing the town of Amboy. It turns westward in Bureau County and flows into Henry County, where it roughly parallels the Hennepin Canal and passes the towns of Colona and Green Rock. It joins the Rock
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.