The prairie ecosystem of Illinois once supported a diversity of mammal species including bison, elk, wolves and prairie dogs. European settlement of the prairies starting in the early 1800s led to the destruction of prairie habitat and the near elimination of large mammal species. Today conservation efforts focus on restoring prairie lands and reintroducing some mammal populations.

1. http://www.museum.state.il.us/mus
link/prairie/htmls/eco_mammals.ht
ml
http://www.inhs.uiuc.edu/~kenr/prai
riesettlement.html