Place
- Ohio--Harrison County1
- Ohio--Henry County1
- Ohio--Highland County1
- Ohio--Holmes County1
- Ohio--Huron County1
- Ohio--Jackson County1
- Ohio--Knox County1
- Ohio--Lake County1
- Ohio--Lawrence County1
- Ohio--Licking County1
- Ohio--Logan County1
- Ohio--Lucas County1
- Ohio--Mahoning County1
- Ohio--Vinton County1
- Olentangy River1
- Ontario, Canada1
- Ottowa River1
- Pickerel Creek1
- Pine Creek1
- Pipe Creek1