It flows west into northeast Oklahoma , then southwest and south through the mountains of eastern Oklahoma , past Scraper and Tahlequah . South of Tahlequah , it passes through the reservoir Tenkiller Ferry Lake . It joins the Arkansas River downstream of Gore and upstream of Robert S. Kerr Reservoir , approximately southeast of Muskogee . Together with its tributary streams , it has a drainage area of . The town of Tahlequah on its banks was the western terminus of the Trail of Tears
Trail of Tears
Trail of Tears
Illinois River (Oklahoma)