List of U.S. Counties Named After Rivers - O

O

• Oconee County, Georgia: Oconee is named for the Oconee River that forms part of the county's border
• Ohio County, Indiana: Ohio is named for the Ohio River.
• Ohio County, Kentucky: Also named for the Ohio River. When the county was formed, the river formed its northern boundary, but no longer does after several new counties were carved from it.
• Ohio County, West Virginia: Also named for the Ohio River.
• Ontonagon County, Michigan is named for a river called Nantounagon on an early French map.
• Otter Tail County, Minnesota: Otter Tail is named after Otter Tail Lake and Otter Tail River. The river was named by the Ojibwa for its long sandbar shaped like an otter's tail.
• Osage County, Kansas: Osage is named for the Osage River.
• Oswego County, New York: Oswego is named for the Oswego River.
• Ouachita County, Arkansas: Ouachita is named for the Ouachita River.
• Ouachita Parish, Louisiana: named for the Ouachita River