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 Wood River receives the tributary streams of Warm Springs Creek and Trail Creek. Below Ketchum, it is joined by the East Fork Wood River at Gimlet before passing by the small cities of Hailey and Bellevue. Continuing south, the river enters the Wood River Valley, the northern part of Magic Valley, after which it flows into Magic Reservoir. A tributary stream, Camas Creek, joins the river in Magic Reservoir. Below Magic Dam, the Big Wood River enters Lincoln County, passing by many lava beds and irrigation canals before entering Gooding County. Just west of Gooding, the Big Wood River joins the Little