Waterloo and Marshall, Jefferson and Dane Counties. February, 1970. Altitude c. 5,000 ft. The snow cover of this winter scene highlights a swarm of drumlins. Slopes of many of these parallel hills are wooded, in contrast to the surrounding cropped and pastured farmland. The drumlins were deposited by the Green Bay Lobe of the Wisconsin Glacier about 20,000 years ago as it moved to the southwest (left bottom of frame).