The Kokosing River (ko-KO-sing) is a tributary of the Walhonding River, 57.2 miles (92.1 km) long, in east-central Ohio in the United States. Via the Walhonding, Muskingum and Ohio Rivers, it is part of the watershed of the Mississippi River, draining an area of 482 square miles (1248 km²). The Kokosing River rises in Morrow County, northeast of Mount Gilead, and initially flows southwardly. It turns eastwardly near Chesterville and flows through Knox and Coshocton Counties, passing the communities of Mount Vernon, Howard and Gambier. In western Coshocton County the Kokosing joins the Mohican River to form the Walhonding River, about 2 miles (3 km) northwest of Nellie. Upstream of Mount Vernon, the Kokosing collects its largest tributary, the North Branch Kokosing River, which rises in Morrow County and flows southeastwardly through Knox County, past Fredericktown.