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
Big Thompson River tributary flows east, through the town of Glen Haven, where it merges with the Big Thompson River in the town of Drake, in the Big Thompson Canyon. From Lake Estes, the river descends 1/2 mile (800 m) in elevation through the mountains in the spectacular 25 mi (40 km) Big Thompson Canyon, emerging from the foothills west of Loveland. It flows eastward, south of Loveland across the plains into Weld County and joins the South Platte approximately 5 mi (8 km) south of Greeley. It receives the Little Thompson River approximately four mi (6 km) upstream from its mouth. Water