I never did get any details from IDNR about this weekend's events, but The River had a blurb on their site:
Northern Illinois Hunting and Fishing Expo 9/25
Sep 25, 2011 9:00am - 5:00pm
Join 95.9 The River for the Northern Illinois Hunting & Fishing Expo on Sunday, September 25th from 9am-5pm at Silver Springs State Park in Yorkville! (map) It's a FREE event for the whole family with demonstrations from Master anglers, seminar booths, Kids Fishing Pond stocked with Bluegills, you can paddle your own canoe, climb a rock wall. Don't forget the Archery Ranges with a 3D Shoot! The River Road Crew will be out with music, games, and prizes. Scott Mackay will also be out that day from 12pm-3pm!
So there you have it. If I go you'll hear about it.