Marys River (Illinois) River basin: Marys River (Illinois) Marys River is a tributary of the Mississippi River in Illinois. It drains a small watershed between the Big Muddy River and the Kaskaskia River. It joins the Mississippi just southeast of Chester, near Kaskaskia. Because of its proximity to Kaskaskia — the capital of Illinois Territory and the first capital of the State of Illinois — Marys River was the site of early settlements leading into the interior of Illinois. Marys River is approximately in length. The following cities and towns are in the Marys River basin: Parts of the following counties are in
Muddy River (Nevada) to the Colorado River and followed it westward. In 1844, the expedition of John C. Frémont discovered a cutoff route that avoided the Colorado River, following a route between Resting Springs in California, and the Virgin River Valley that passed through Las Vegas Springs and crossed the Muddy River near modern Glendale. Mormon pioneers blazed a wagon road from Salt Lake City to Los Angeles along this pack trail in 1847, followed by Forty-niners attempting avoid the winter snows of the Sierra Nevada Mountains, and wagon trains of Mormon colonists on their way to settle in San Bernardino in 1852.