The Black Hills basically functions around tourism, year round. There is no major industry to speak of in this area. There are a few factories, but not the industrialism that other metro areas see. The northern hills gets more winter tourism, because they have the resources for it (ski and snowmobile areas). There are public lands to hunt during every season. While you won't be falling over other hunters, they are there. Also, don't expect anyone to let you in on the "good" spots - you'll have to figure that out on your own!
There are cabins and campgrounds that stay open year round and cater to hunters in the winter time.