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
Big Muddy Creek (Missouri River tributary) Fort Peck Indian Reservation. It joins the Missouri west of Culbertson. It was explored in 1805 by the Lewis and Clark Expedition, who called it Martha's River in their journals and noticed on their return voyage in 1806 that it had changed its mouth on the Missouri. Along with the Milk River and the Poplar River, it is one of three waterways in Canada that drain into the Gulf of Mexico. Big Muddy Creek has also been known as: Big Muddy River, Little Yellow River, Martha River, Martha's River, Marthas River, Marthy's River and Park River. Big Muddy Creek (Missouri