The Olentangy River rises in Morrow County approximately 2 mi (3.2 km) southeast of Galion, near Blooming Grove, flowing through Galion and northwest towards Bucyrus, where it then turns south and flows through Eastern Marion County, Ohio (where it is still locally known as the Whetstone River) before flowing south into Delaware County. The river continues southward towards the communities of Delaware, Powell, Worthington, and the village of Riverlea, before reaching Columbus and the campus of Ohio State University, before joining with the Scioto River in downtown Columbus.