Not necessarily. As I've stated before, Illinois water law is extremely confusing and vague, AT BEST. Numerous tracts of land were never ceded to the corps of engineers when the dams were built therefore, even though the corps controls the water and you can fish, but once you drop anchor, you are tresspassing. Few if any of the duck clubs will push this for fishing, but if you are hunting, they WILL have you arrested. That is why I posted to talk to the CPO's in the area's you want to hunt, as I know there are several problems with hunting on the Illinois River.
I am much more familar with the Mississippi River. Two pools on the Miss., pools 19 & 20 are privately owned, created by the power dam at Keokuk by Union Electric (now Ameren). You can fish all you want. Owners usually don't enforce anchoring for fishing most of the year, but the CPO will be there in minutes if you do it during duck season.
Semper Fi, Marines
Casey 1997-2011 RIP