If you are looking for a fun, free, family activity. I highly recommend Cabella's sporting goods store. It is like a zoo for outdoor animals, has a live fish pond and tanks. There is also free fudge tasting, and a restaurant if you get really hungry. (However we opted for the dollar hamburgers at the nearby McDonald's.)
We had so much fun and made a lot of fun memories. Here is a fun clip from our trip. Enjoy!