Atmospheric bulk deposition was collected on a monthly basis in the Lake Michigan basin from September 1975 through December 1976 to determine the atmospheric loading of trace elements to Lake Michigan. The sampling network consisted of bulk collectors located at 21 locations in the northern and southern basin. The percentage of total atmospheric deposition falling in the southern basin was: Fe-74%, Al-71%; Mn-75%; Zn-67%; Cu-62%; Pb-78%; Cd-74%; Co-approximately 56%; Ca-79%; Mg-62%; Na-65%; K-61%. Atmospheric loading rates reported are in general agreement with estimates made by others from emission inventories and aerosol concentrations. The geographical distribution of trace element loading implicates the southern periphery of Lake Michigan as the principal emission source area. (Copyright (c) 1980 by D. Reidel Publishing Co., Dordrecht, Holland, and Boston, U.S.A.)