There is an established Gray Wolf population existing in the Western Great Lakes states of Michigan, Minnesota and Wisconsin. There have been sightings and accidental killings of dispersing wolves in the states of Illinois, Indiana, Nebraska, North and South Dakota and Iowa.
[HTML] Demographic and component Allee effects in southern Lake Superior gray wolves; JL Stenglein, TR Van Deelen – PloS one, 2016 – journals.plos.org
Taxonomy, morphology, and genetics of wolves in the Great Lakes region
RM Nowak – … of Gray Wolves in the Great Lakes Region of the …, 2009 – Springer