I assume you are in SW MI? What tires are on you're MTB now?I live about about 60 miles east of Chicago, and the winters are harsh one year, and mild the next.
These look interesting : Continental Top Contact Winter
The TopContact Winter was designed for use in fall and winter. The tread compound contains sharp-edged granules, creating additional high-grip edges on the tread surface.
I have no experience with them, but the design looks interesting