Casey Creek (Illinois) and Atchison Creek. Gun Creek, which enters Rend Lake on the east side, might also be considered a Casey Creek tributary. Casey Creek (Illinois) Casey Creek is a major tributary of the Big Muddy River in Illinois, United States. It is about long, measured from the junction of its arm of Rend Lake with the arm formed by the Big Muddy River. Casey Creek is shown on federal maps as Casey Fork, following a 1967 decision by the U.S. Board on Geographic Names. It is named for Zadok Casey, a congressman from Illinois in the early 19th century. Casey Creek
River Grove, Illinois River Grove, Illinois River Grove is a village in Cook County, Illinois, United States. The population was 10,227 at the 2010 census. River Grove is located at (41.925830, -87.840135). According to the 2010 census, River Grove has a total area of , all land. Just as nearby Elmwood Park and Oak Park are named after their historic elm and oak trees, River Grove gets its two-part name first from the community's shallow muddy plains river, and second from the majestic groves of American ash trees lining shore of the (Aux) Des Planes River "Bottomland." Credit goes to the village's early