If there is a place where these birds could survive it would have to be someplace like the Cache River area. The Cache River Refuge contains a variety of wetland communities including some of the most intact and least disturbed bottomland hardwood forest in the Mississippi Valley region. A vast place of primeval beauty.
Makes sense, and it's not one of the places that people have done really intensive searches in the past. Last major search I heard of was at Pearl River in Mississippi/Louisiana.
The big question will be, how many of them are there.