I'm not sure if Kansas is officially part of the Bible Belt, but I think the state is predominantly Catholic, judging by my time spent working there.
Lots of Catholics in the KC-Overland Park area, due to the large migration of Southern Germans, Irish, and (to a lesser extent) Italians to that area at the turn of the last century. Rest of the state is very mixed. Wichita has a large population of both Catholics and Evangelicals, with few mainliners.
I believe Louisiana is the most Catholic state outside of the Northeast. Rhode Island is the only state where Catholics are in the majority, btw.