I drive from Minnesota to LA a couple times a year, and the opportunities depend on the route you take, and how far north you go before you turn east (or how far east you go before you turn north.) One key place for that trip is Kearney, Ne, which is where a lot of people stop (lots of motels.) The thing is, it's on the Platte River, with lots of birds around, and a big Sandhill Crane center (an Audubon Society center, I think -- I've never been there.) The best viewing times are in the Spring, but they do have some cranes coming through in late September. There are also quite a few cranes around in northern Wisconsin in September...I often see them in the Hayward area.
I don't know if you have an interest in ringneck pheasants, but there are areas in southeastern South Dakota where they are more common than pigeons...whole ranches devoted to pheasant hunting. I would suspect that one of those places could tell you where to set up a blind for pheasant-watching...
