The river flows south into Cherry Valley Township then to the southwest into the village of Baldwin, where it is joined by Sanborn Creek. The GNIS entry for Baldwin River records the mouth as being on the Sanborn Creek at . However, USGS topographic maps show the stream continuing southwest into the Pere Marquette River labeled as both the Baldwin River and Sanborn Creek. The GNIS entry for Sanborn Creek indicates it is also known as the Baldwin River. The stream empties into the Pere Marquette at and thence into Lake Michigan.
