Midwestern Vacation Ideas

My husband and I are trying to figure out a fun, not totally commercialized place to take our kids for a week this summer. We're thinking along the lines of an outdoorsy area where we might be able to rent a cabin & do stuff like swim, paddle boats, fishing, mini golf, hike trails & go to local shops & restaurants. We're not thinking something like Wisconsin Dells or Great America. Starved Rock is a great idea, but we're going to go there this fall and do the indoor water park thing, so we're just looking for something farther away that is a little tourist-y, but not totally commercial. We live right next to Peoria, IL and would like to drive about 6 hours or less to get to where we're going. Does anyone have a suggestion of an out-of-the-way place that might be what we're looking for? The more suggestions, the better!! Thanks so much!