Hello
tsmcarr, welcome to Flyertalk^
I can't answer your question about MKE, but unless you are north of MKE, ORD (O'hare) and RFD (Rockford, IL) might be options for you to consider as there are direct to beach flights.
wish you luck in your search, there are 13 airlines that service MKE
http://www.mitchellairport.com/ I would hope one of them would have a flight you are looking for.