I believe there is a meetup group based right outside of Dayton. Indianapolis also has some events every now and then, and most definitely has a fair sized poly community (the Indy community didn't seem very event oriented, but the people are there and looking). A bit of a drive for random events, but indicative of an active poly community in the somewhat near vicinity.
I agree about OKCupid, though. Even if you're nervous about putting your photo out there, you can make a profile and search for other profiles that mention poly. It's a great way to connect, find friends, and potential dates.