The thing about hunting in the midwest is that most people know what coins are silver and keep them. You might find more CWRs but I don't think you'll find more silver. Many in the midwest are "hard money" enthusiasts and having hunted the midwest I've found a distinct lack of CWRs because around here every bank no matter how small has a coin machine.
There is also a lack of historical money in the midwest because until recently (recently in historical terms) it was very sparely populated and mostly agricultural, meaning that there weren't very many people and they were mostly poor.
There are also many towns that grew only recently. For example, although the town I live in has a recorded history going back to the 1830s, it was inhabited by less than 100 people until about the 1950s and under 1000 people until the 1970s, today it has about 13,000 people. That is pretty typical for larger midwestern towns. It makes metal detecting and CRHing rather poor when compared to the coasts where vast amounts of history, people and wealth coexisted.
