Sugar River

Quick Facts

Hydrologic Unit Code (HUC-12):  070900040803

Area:  23.6 square miles (15,124 acres); 8% of Lower Sugar River Watershed/2011

Counties:  Wisconsin: Rock County/Avon and Newark Townships; Illinois: Winnebago County/Harrison, Laona and Shirland Townships

Municipalities: None

Primary Land Uses:  Agriculture (cropland 57%, pasture/hay 13%), Forest (11%), Water/wetland (12%) of landcover/2011

Points of Interest: Two Natural Areas, Shirland Railroad Prairie and Sugar River comprised of three forest preserves, Sugar River Alder, Colored Sands and Sugar RiverSand Bluff Bird Observatory within Colored Sands Forest Preserve; two nature preserves, Sugar River Alder and Colored Sands Bluffs within corresponding forest preserves. 

Water Quality:  The section of the river from the Wisconsin border to Otter Creek, approximately five miles, is one of the region’s few remaining undeveloped, fully functioning high-order streams.

At a Glance 

  • The vast majority of the land area of this subwatershed is located in north-central Illinois in Winnebago County. To the northeast a small area extends above State Line Rd into Rock County, Wisconsin. 
  • In the Illinois portion of this subwatershed are two Natural Areas (NA), Shirland Prairie NA (1.75 ac) and the much larger Sugar River NA (3249 ac). The latter NA is comprised of three nearly contiguous forest preserves: Sugar River Alder, Colored Sands and Sugar River.
  • From the Wisconsin border to its confluence with the Pecatonica River, approximately 10.7 miles of the sinuous Sugar River flow through these adjoining forest preserves where prairies, bottomland and upland forests, marshy areas and steep sand bluffs serve to protect the river corridor’s rare and unique plants and animal habitats and to offer refuge to nesting and migrating birds. For a more in depth narrative on the Sugar River click here.
  • Watershed Rapid Assessment Survey (WRAS) data collected by trained LSRWA citizen science volunteers in 2011 and 2012 (data on file with LSRWA) rated the watershed to be in fair to good condition. For a map of WRAS data points click here.

Learn More

Two nature preserves--the Sugar River Alder NP and Colored Sands NP--exist within two of the forest preserves by the same name. How does a nature preserve differ from a forest preserve? In Illinois, forest preserves are county-owned and managed open spaces set aside to protect the beauty of the natural landscape and for public access to natural resources for recreation and outdoor education. Some areas of the county forest preserves are designated Illinois nature preserves. These parcels are recognized and protected as last remnants of Illinois wilderness harboring unique habitats and rare plants and animals, and they are permanently protected by state law. Minimally developed, both are open to the public for hiking and nature observation.   


Outdoor recreational opportunities abound: 

Try paddling the Sugar from Yale Bridge Rd to Two Rivers Forest Preserve boat launch on the Pecatonica River off Harrison Rd - about seven miles. This section is passable, but strainers are plentifull and at low water level sandbars can be problematic. The put-in has picnic tables, parking and bathroom facilities. For a trip report of this paddle click here. If you are an Illinois resident your canoe/kayak no longer is required to have a license or stamp.  

Are you interested in birding? A visit to the Sand Bluff Bird Observatory, a bird banding station is always interesting. It's free and open to the public on Saturdays and Sundays during the fall and spring migrations. Call ahead (815-629-2671) to confirm dates of operation. A good time to visit with children (adults, too) is during May for Birdfest, a celebration of wild birds. There is plenty to see and do: guided tours, crafts, live bird exhibits, lectures, refreshments and opportunities to watch the bird banders at their trade.

How about camping? Camping is available only at the Sugar River Forest Preserve.Walking a trail within Colored Sands State Forest

Hikingfishing and nature observation are additional activities you can pursue at all of the forest and nature preserves. 

Did You Know?

The Illinois section of this subwatershed is designated as the Sugar River Resource Rich Area (RRA) in the Illinois Natural History Survey of 1996.

The Sand Bluff Bird Observatory, a bird banding station is situated within the Colored Sands Forest Preserve. It is one of the largest small bird banding stations in the country open to the public. 

The Indian word "ke-pot-ah" which means "sweet water" is reported to be the basis for the naming of the Sugar River and is thought to be referring to the sandy basin through which it flows. 

For a printable PDF map of Sugar River Subwatershed click here.


2011 National Landcover Database: