I had a friend catch a "18 inch" crappie last year. (I saw a pic, if it wasn't it was darn close.) I about lost it, and mentioned something about state record. He laughed and said something about it sitting on a shelf in his fridge.
I grew up near that lake and near Murphboro. I fished at Crab Orchard lake, near Carbondale also.
But the best Lake for spiny rays, in my opinion, was Cedar Lake a bit further south. Loaded with hungry blue gills. But none that size.