Advances of the Green Bay Lobe deposited at least three till sheets that are late Woodfordian age and younger. In the western part of the lowland, the tills are distinguished on the basis of stratigraphic position, texture, color, and depth of leaching. In the central part of the lowland, tills are covered by lacustrine sediment; on the east side, however, a similar sequence of tills is present. Here till units are distinguished on the basis of stratigraphic position, magnetic susceptibility, and depth of leaching. The Chilton till, which is overlain by Two-creekan wood at one locality, is correlative with the Valders Till of the Lake Michigan lowland, as is the age-equivalent Kirby Lake till. One Greatlakean till, correlative with the Two Rivers Till of the Lake Michigan lowland, overlies forest beds at several localities.