I've never ran in a MAO prelim but I have good friends that run 3 prelim pageants to Miss Hawaii.

Turn for the Judges is a decent pageant resource that lists names for current titleholders for every pageant out there. In addition to that, they also provide links at the bottom of the page so you can contact the local pageant people. Not all prelim pageants have links to websites, but you can use the few out there to point you in that direction. If those don't help, then I'm sure you can find a contact person at http://www.missil.org Good luck!