I am in Evansville in Southwest IN. We have "fish days" at local tractor supply or Rural King stores about once a month. Ours is from Andry's fish farm and their schedule is on their website.
A lot of times the store will have fliers out or behind the counter for the next planned date. The schedule varies though - just because they are there the first weekend in May, they may be the third weekend in June.
Check the stores to find out the name of the hatchery, then go to their websites or call them. Fish days are fun, long lines quite often, but the stories and camaraderie in the lines is pretty great.