Hi Eric,
I think these destinations are in the area you are considering:
Crater of Diamonds State Park in Arkansas Go
here to see the web site. In this park, it is finders keepers. Who knows, you may find a large diamond and be set for life.
Hot Springs National Park, Arkansas Go
here to see their web site. This is close to Crater of Diamonds. You can dig for your fortune one day and get a great massage and be treated like royalty the next day.
Branson, MO. Go
here for the web site. There is lots to do. On the outskirts of Branson there are fishing and hiking opportunities.
I've been to all these places (with grand kids). If you have additional quesitons, let me know.