Tulsa here and yeah this area has a lot of swingers but no real cohesive poly community that I have found so far, which is frustrating. That and the general culture here is not favorable to non monagamy in general.
If we had enough people we could actually set up a meet and greet of some kind but us poly types in the NE Oklahoma area seem few and far between. On another thread that I posted in earlier OkCupid was suggested. I signed up this week and am giving it a try. It does seem poly friendly. Look me up and say hi