Pecatonica River

Pecatonica River
The Pecatonica River in the Pecatonica River Woods State Natural Area in Iowa County, Wisconsin
Map of the Pecatonica River watershed
Physical characteristics
Source 
  locationIowa County northwest of Cobb, Wisconsin
  coordinates42°58′44″N 90°20′37″W / 42.9788889°N 90.3436111°W / 42.9788889; -90.3436111 (Pecatonica River origin)
  elevation1,188 ft (362 m)
Mouth 
  location
Confluence with the Rock River at Rockton, Illinois
  coordinates
42°27′00″N 89°04′30″W / 42.45°N 89.075°W / 42.45; -89.075 (Pecatonica River mouth)
  elevation
712 ft (217 m)
Length194 mi (312 km)
Discharge 
  locationShirland, Illinois
  average2,011 cu/ft. per sec.
Basin features
ProgressionPecatonica River → Rock → Mississippi → Gulf of Mexico
GNIS ID415503

The Pecatonica River is a tributary of the Rock River, 194 miles (312 km) long, in southern Wisconsin and northern Illinois in the United States.

The word Pecatonica is an anglicization of two Algonquian language words: Bekaa (or Pekaa in some dialects), which means "slow", and niba, which means "water", forming the conjunction Bekaaniba or "Slow Water".

It rises in the hills of southwest Wisconsin, in southwest Iowa County, 2 miles (3 km) west of Cobb. It flows south, then southeast, past Calamine and Darlington. In southeast Lafayette County it receives the East Branch Pecatonica River, approximately 8 miles (13 km) north of the state line. It flows south-southeast into Illinois, past Freeport, where it turns east, then east-northeast, receiving the Sugar River near Shirland in northern Winnebago County, 5 miles (8 km) south of the state line. It joins the Rock at Rockton, approximately 15 miles (24 km) north of Rockford.