I know of one geared more toward the Midwest United States, although people from other areas are welcome to it if they want to know of things going on in the area or would just enjoy seeing the articles posted. We have people in there from Washington state, so it really isn't exclusive to the Midwest, just heavy there.
If you are curious about it, you can PM me. I might be able to put you in contact with some groups in the Western U.S. even if I'm not part of them.
There is one for the Northwest US & there is one called "poly friends all over". Both of which I am in, one of which I am a moderator of.
If you are interested in being added to either, send me a pm and I will tell you how to make that happen.
If you hover your cursor over someone's user name and click once, a drop down list will appear. One of the options is to send a private message (PM). You can also select 'view public profile' on the drop down list and look at the profile. There are a few options there on how to send a private message.