SUGAR RIVER
Cone flowers in bloom in the Sugar River RRA, photo by Mike Jeffords, INHSSand deposited by the wind after the last glaciation formed dunes and ridges aloong the Sugar River. The dunes and ridges were eventually stabilized by forest and prairie vegetation. Sugar River is a migration route for birds; over 150 species have been banded at the bird-banding station in Colored Sands Bluff Nature Preserve.

Map of Site
Land Cover Map of Site

SIZE: 15,144 acres 23.7 square miles

LOCATION: North-central Illinois bordering Wisconsin; Winnebago County.

The Sugar River RRA is characterized by a wide, wooded riparian corridor of floodplain forest and upland woods. It is the smallest RRA. The Sugar River area is along an important bird migration route and provides habitat for several unusual amphibians and reptiles.

LANDCOVER: The predominate landcover type is cropland (45%), followed by grassland (33%). This site has the second highest percentage of grassland among the RRA's. The site is 18.5% wooded (8% upland and 10.5% bottomland forest). The percentages of bottomland woods and nonforested wetlands are relatively high, but the total acerages are low, reflecting the site's small size.

NATURAL AREAS: The Sugar River Natural Area occupies 20% of this RRA. A small prairie is the only other Natural Area in this RRA.

BIOLOGICALLY SIGNIFICANT STREAMS: The Sugar River RRA has 4.5 miles of biologically significant streams.

HERITAGE SITES: Twenty-four Heritage Sites occur in this RRA. There are three significant community types, 12 plant species, and four animal species.

STATE AND FEDERAL LAND: There is no state or federal land in this RRA.

NATURE PRESERVES: There are two Nature Preserves in this site. Natural features include bluffs, sand savanna, and prairie.

NATURAL DIVISIONS: This site lies in the Rock River Hill Country (84%) and Northeastern Morainal (16%) Divisions.

SUMMARY OF SITE CHARACTERISTICS: SIZE, BIOLOGIC RESOURCES, AND PUBLIC LANDS
Total Acreage15,144
Natural Areas
    Acreage
2,993
    Number
2
Biologically Significant Stream Mileage4.5
Natural Heritage Sites24
State Land
    State Parks
0
    State Conservation Areas
0
    State Forests
0
    State Fish & Wildlife Areas
0
    Acreage
0
    Percentage of RRA
0.0
Federal Land
    Acreage
0
    Percentage of RRA
0
LANDCOVERAcres% of RRA
Upland forest1,208.877.98
Bottomland forest1,581.9810.45
Wetland- nonforested424.102.80
Grassland4,979.9732.88
Cropland6,803.8144.92
Urban/Built-up16.860.11
Water129.460.85
Total15,145.0599.99

ILLINOIS NATURAL AREAS INVENTORY SITESAcres
Shirland Railroad Prairie4
Sugar River2,989
BIOLOGICALLY SIGNIFICANT STREAMSMiles
Sugar River, Otter Creek4.5
NATURAL HERITAGE CATEGORIES
CommunitiesOccurrencesTypes/Species
Lake11
Prairie22
Threatened and Endangered Animals
Mammal11
Threatened and Endangered Plants
Plant-Dicot117
Plant-Monocot22
Plant-Fern/Fern Ally33
STATE AND FEDERAL LANDAcres
State Parks0
State Conservation Areas0
State Forests0
State Fish and Wildlife Areas 0
Federal Land0

ILLINOIS NATURE PRESERVESAcres
Colored Sand Bluff56
Sugar River Alder Site167

NATURAL DIVISIONSAcres in RRA% of RRA% of Division
Rock River Hill Country12,67583.70.8
Norteastern Morainal2,47016.30.1

Return to Table of Contents