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
Southern Illinois River-to-River Conference Southern Illinois River-to-River Conference The Southern Illinois River-to-River Conference (SIRR) is a high school athletic conference represented by 12 schools in southern Illinois. The conference is divided into two divisions. While technically in the same conference each division crowns its own champion, and each winner is regarded as the conference champion as if they were in two separate conferences. Schools are only required to play other schools within their own division although cross-divisional play is very common. Seven of the charter members of the River-to-River Conference were members of the old Southwest Egyptian Conference. Around 1991, the Southwest Egyptian was