City of Casey issued the following announcement on June 19.
The annual Illinois Free Fishing Days celebration is slated for June 19 – 22, once again coinciding with Father's Day Weekend. Free Fishing Days is a four-day celebration of fishing in Illinois when anglers can fish without purchasing a fishing license, salmon stamp or inland trout stamp. Please make sure to check the hours of your favorite spot before you head out. Looking for where to go fishing in your area?
https://www.ifishillinois.org/profiles/selector.php
Original source can be found here.
Source: City of Casey