The moraine was created when the
Green Bay Lobe of the
Laurentide Ice Sheet, on the west, collided with the
Lake Michigan Lobe of that glacier, on the east, depositing sediment. The western lobe formed Green Bay,
Lake Winnebago and the
Horicon Marsh. The major part of the Kettle Moraine area is considered interlobate moraine, though other types of moraine features, and other glacial features are common. The moraine is dotted with
kettles caused by buried glacial ice that calved off the terminus of a receding glacier and got entirely or partly buried in glacial sediment and subsequently melted. This process left depressions ranging from small ponds to large lakes and enclosed valleys. Water-filled kettles range in depth from . The
topography of this area is widely varied between the lakes and kettles and the hills of glacial deposits, which can rise up to from the lakes. The largest include Holy Hill, Pulford Peak and Lapham Peak.
Elkhart Lake,
Geneva Lake, and
Little Cedar Lake are among the larger kettles now filled by lakes.
Kames are also found in the Kettle Moraine area, and are mounds of compressed glacial till. == Recreation ==