The effects of repeated glaciation have left their mark on the Superior Upland. The present glacial topography is the product of the most recent glaciation that ended just 10,000 years ago. During the Late Wisconsin, the last glaciation of the Pleistocene Epoch, a massive continental ice sheet grew first in the north, then gradually expanded southward. Several thick finger-like lobes of glacial ice engulfed the region as they moved through the Superior basin. Rocks of all sizes were plucked and scoured from farther north and carried along by the icy mass. When the continental ice sheets melt, they left behind an assortment of rock called glacial drift that covers much of the Superior Upland landscape.