Field Systems and Frost Drainage in the Prehistoric Agriculture of the Upper Great Lakes

Abstract
Hypotheses regarding functions of prehistoric ridge-and furrow agricultural fields from Wisconsin and Michigan have been tested by resorting to data derived from experimental agricultural fields. The primary function of these fields was frost drainage in an area that was marginal to agriculture because of a minimal frost-free growing season. The time of introduction and disappearance of these features may correlate with climatic changes in North America from A.D. 1250 to 1550.