The two counties which share the northern tip of the Lower Peninsula of Michigan, Emmet on the west and Cheboygan on the east, have long been taken to define the principal "region" under study by the University of Michigan Biological Station, situated since 1909 on Douglas Lake in Cheboygan County near the Emmet County line.
Voss, Edward G.
"Moths of the Douglas Lake Region (Emmet and Cheboygan Counties), Michigan: II. Noctuidae (Lepidoptera),"
The Great Lakes Entomologist: Vol. 14
, Article 4.
Available at: https://scholar.valpo.edu/tgle/vol14/iss2/4