There are people in your area
I think we are neighbors...
And if you have not found them yet, there are people in your area but you are correct very conservative small city.
I will tell you most of the folks are not really Poly more casual sex swingers. Some are closed and want to have a casual sex relationship with just one person or cpl, but not really poly as the emotion is typically not there.
I find around here even being bi is a pain...people straight and gay think your on the fence and need to choose a side...Good luck with your search!