I went to college at SIU. There are 2 9-hole courses on campus. One of the courses is by the rec center and the other is by campus lake.
The course by the rec center is not very fun to play. You will probably spend more time waiting for people to get out of your way than you will actually playing. 5 of the holes are on the side of the street that the dorms are on, and the other 4 holes are across the street in front of the rec center. Also the baskets are very old and only have one ring of chains.
The campus lake course is much better. You will probably still spend some time waiting for pedestrians but it's not nearly as bad. The water comes in to play on three holes, and it is very common (and dangerous) to see people jump in after their discs. This course also has alternate tee pads that the club utilizes to make up an 18 hole round.
The new course in town, Hickory Ridge, was opened up after I left. My senior year we started working on the course but it was very slow moving. From what I've heard it still rough around the edges, but having an 18 hole course with nice baskets is awesome no matter how rough it is.
There is also a sports club at the college. I would recommend checking out their Facebook page, Southern Illinois University Disc Golf. They usually travel to 1-2 collegiate tournament every year and also they have weekly leagues. They are having their 8th Annual Ace Race in October.
"Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!"
-- Hunter S. Thompson