Michigan Department of Natural Resources

Geological Survey.  When were Michigan state parks and recreation areas established? (PDF). Michigan Department of Natural Resources. [April 6, 2020]. （原始内容

to Michigan Sand Dunes, pp. 30-32. The University of Michigan Press.047203118X Grand Mere. Natural Areas. Michigan Department of Natural Resources. [March

（原始内容存档 (PDF)于2020-10-18）.  Michigan DNR celebrates 100 years of state parks (PDF). Michigan Department of Natural Resources: 10–11. [April 28, 2020]. （原始内容存档

Area. Michigan Department of Natural Resources. [2020-07-19]. （原始内容存档于2020-10-16） （英语）.  Joel Greenberg. A Naturalist's Tour of Southern Lake Michigan. [2020-07-19]

Geological Survey.  When were Michigan state parks and recreation areas established? (PDF). Michigan Department of Natural Resources. [April 7, 2020]. （原始内容存档