If you want big gills my three favorites besides a few private ponds are Jewell State lake, Mcpherson State and then Milford. Ottawa doesn't have good size to them from what I have experienced.
Caught some bigguns at Jewell last Winter through the ice!! You were with me one trip!
"I envy not him that eats better meat than I do; nor him that is richer, or that wears better clothes than I do; I envy him, and him only, that catches more fish than I do."
Izaak Walton, 1653