September, 1943 Brown & YEAGER: 
SURVEY OF FuR RESOURCE 
443 
Fig. 5—Northwest Hills habitat type. 
and absence of intensive agriculture make this region well adapted to skunks, gray foxes and 
badgers. A scene from Jo Daviess County is pictured here. 
agricultural areas and in them are located 
most of the drainage ditches of the region. 
Glacial Lakes.—In size, this is the 
second smallest of the eight survey regions, 
fig. 2. It contains only 1,638 square miles. 
Small glacial or kettle lakes are scattered 
rather uniformly over the entire area. 
Extensive cattail and bulrush marshes ad- 
join many of these lakes, forming excellent 
muskrat habitat, figs. 7 and 21. Varying 
amounts of emergent and floating vegeta- 
tion in the lakes supplement the food sup- 
ply. Water levels approach stability. “Che 
winters are usually severe. The topog- 
raphy is nearly level to rolling, and the 
soil is a heavy sandy loam. Woodland 
Forested hills, rolling terrain, permanent streams 
found in the region is mainly on estates; 
farmer-owned woodland is largely pas- 
tured. 
Black Prairie—The well-known Illi- 
nois black prairie is the most extensive 
general soil type in the state, fig. 2. The 
fur survey region set up for this soil type 
is 16,462 square miles in area. Streams, 
valleys and occasional moraines are the 
only deviations from its slightly rolling 
contour. Drainage ditches, fig. 8, and tile 
lines occur throughout the region, and 
most of the water from them enters the 
Illinois River system. 
The ditches and some of the streams 
afford fair to good muskrat and mink 
Fig. 6—River Bluffs and Bottoms habitat type. Forest-inhabiting species such as raccoons, 
opossums and gray foxes occur in greater density here than in any other region in Illinois. The 
combination of aquatic and forest areas makes this region ideal raccoon range. Shown here is 
one of several connecting channels between the Illinois and Mississippi rivers, near Grafton. 
