Visiting the 'Driftless Area' - origin of Lyme disease ticks in the Midwest?

'Lyme disease' is named for Lyme, Connecticut, where spread of the disease by ticks was first recognized.  But the earliest case report of this disease in the U.S. in fact came from Wisconsin, on the the edge of the 'Driftless Area' - a rugged plateau that remained ice-free during the Wisconsinan glaciation.  This area is the likely geographic origin of blacklegged tick populations that have expanded rapidly in the Midwest since the 1950s.