1984 – 1985
Kohout, John
1981
1987
Stickney, William S.
1987
1981
Larkin, Joe
1981
Northern Illinois University Laboratory for Cartography and Spatial Analysis
October 1982
Koehler, Lee
October 1982
Koehler, Lee
October 1982
Koehler, Lee
October 1982
Koehler, Lee
October 1982
Koehler, Lee
May 1 1980
U.S. Forest Service