Muskrat houses in three Illinois 
habitats: Turner Lake, Chain-o’- 
Lakes State Park, Lake County, 
Glacial Lakes Region (top); Lake 
Chautauqua, Chautauqua National 
Wildlife Refuge, Mason County, 
Central Sand Prairie Region (mid- 
dle); Waltersburg, Pope County, 
Shawnee National Forest, River 
Bluffs and Bottoms Region (bot- 
tom). Used principally for con- 
struction were hardstem bulrush 
in the Lake County lodge, marsh 
smartweed in the Mason County 
lodge and cattail in the Pope 
County lodge. In all three cases, 
building material was taken from 
the immediately surrounding area. 
The muskrat, most important Illi- 
nois fur animal, shows considerable 
adaptability to environment. 
