There is some bank access to the river. Just south of the refinery, chain of rocks bridge. Horseshoe lake state park, this was an oxbow of the river. Also, North of the refinery, near Alton, maybe a few spots in between. I’d look on satellite view, see what you find.

A bit farther northeast, Gillespie and carlinville city lakes, not sure about bank access, get ahold of them. Otter lake?