It rises in the hills of eastern Iowa County, approximately 2 miles (3 km) north of Barneveld and approximately 25 miles (40 km) west of Madison. It flows south past Barneveld, Blanchardville, and Argyle, and joins the Pecatonica in southeast Lafayette County, approximately 5 miles (8 km) north of the state line with Illinois.
^U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National MapArchived 2012-03-29 at the Wayback Machine, accessed May 13, 2011