Wood River (Illinois) Wood River (Illinois) Wood River is a tributary of the Mississippi River, which it joins near East Alton, Illinois, to the northeast of St. Louis, Missouri. The Wood River is formed by the confluence of its West and East forks. These come together near where they drop down from the Mississippi bluffs. The natural channel of the Wood River used to follow the Mississippi through the bottoms before joining it. This has been cut off by an artificial channel that runs through flood control structures directly to the Mississippi. The West Fork of the Wood River is long, and the
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