Water levels, locations, depths, and aquifers tapped are given for 112 observation wells. Tabulated data include a listing of ground water reports in Michigan, extremes of water levels for calendar year 1988 and for the period of record, pumpage of most major ground-water users in the State, and water-quality data from selected wells. The two largest municipal users of ground water, were the cities of Lansing and Kalamazoo. In 1988, Lansing pumped 7.8 billion gallons from the Saginaw Formation and glacial deposits and Kalamazoo pumped 7.4 billion gallons from glacial deposits only.