After rising east of the town of Shannon in northeastern Carroll County, the Leaf flows eastward across northwestern Ogle County, past the towns of Adeline and Leaf River. It joins the Rock River from the west between the towns of Byron and Oregon.
^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