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
Course of the Colorado River colorful and intricately sculpted rock formations. The Escalante River, a desert stream which runs through the sinuous slot canyons of Grand Staircase-Escalante National Monument, joins about two-thirds of the way down Lake Powell. The San Juan River, which carries runoff from the southern slopes of the San Juan Mountains and the Four Corners region in Colorado and New Mexico, joins several miles further downstream; it forms an arm of the lake nearly long. Although the San Juan contributes only about one-tenth of the Colorado River flow, it is extremely muddy, contributing as much as 40 percent of the total sediment