The authors of this paper spent the summer of 1920 in western Michigan studying the mammals of the region for the Michigan Geological and Biological Survey. From June 25 to August 4 was spent in the Cisco Lake Region with headquarters on Lindsley Lake; August 6 to August 20 a camp was maintained in the woods four miles southeast of Little Girl’s Point; and from August 20 to September 6 was spent working from a camp on the western shore of Lake Gogebic, about three miles south of Lake Gogebic Station. The first two camps were in Gogebic County, the third in Ontonagon County.