As far as I know, and there are a few that I'm not sure on, the traditional areas are as follows: Minnesota - Kotelnicki Wisconsin - Mannasau Illinois - Luke Nebraska / Arizona - Freund California - Nurse Montana / Oregon / Washington - Breitbach
Those are the ones I'm thinking are accurate, but I could be a bit off. Don't know about ND, SD, Iowa, Missouri, Nevada and Texas (places we've recently received commits from).