You can't go too far wrong with: weather, food, regional witticisms.  The hard part is that anything you might want to ask (i.e. a question about them) can get quickly turned around into a question about you (oh, so you're not from here...) so you have to be quick with the follow-up.

Is it always this cold?
Did you grow up around here?
What's the typical cuisine?
Have you been to all the lakes?
Do you feel close to the wilderness?
Has the town changed much in the last 20 years?
(And surely there are some sports questions you could ask. I can't help here.)

Hi Natalie, I find your story very funny. I don't have much experience about starting a conversation with midwestern looking midwestern people. I once got a lift from South Bend (Indiana) to Urbana-Champaign (Illinois) and that was my big opportunity for such a conversation. I put my foot in my mouth by sneering about women getting married very young to their first boyfriend (as, I then found out, my driver). I made up for it with a dinner invitation; I vaguely recall to have said something controversial even that evening (something about nuns...one of the girls was training as one, I discovered afterwards). So don't take advice from me, I'm a failure.
On the other hand, people commenting on your hair all the time sound a bit rude to me. If this is what they do, maybe you should fire straight back with something about their appearance, like, suggest that with all these fair haired people the Midwest must have certainly hosted in pre-historic times some Viking tribe (I told you not to take advice from me...).
Good luck and all my brown curly-haired sympathy!

Most people will become much more friendly if you let them talk about themselves. In order to do this you should work on  listening  skills which involve mostly concentrating with all your attention on the person and what they are talking about. I have heard generally recommend a 3 to 1 ratio of them talking.
In order to start a conversation, you would pick up some lines like:
Have you lived here your whole life?
Do you have family around here?
or any of the other things mentioned above.
You might also want to read Dale Carnegie.
Good luck