Place
- Ohio--Marion County1
- Ohio--Morrow County1
- Ohio--Pike County1
- Ohio--Scioto County1
- Ohio--Seneca County1
- Ohio--Toledo1
- Ohio--Trumbull County1
- Ohio--Vinton County1
- Ohio--Wyandot County1
- Olentangy River1
- Ottowa River1
- Pickerel Creek1
- Pine Creek1
- Pipe Creek1
- Poland Township1
- Pulaski Township1
- Pymatuning Creek1
- Rocky River1
- Saint Joseph River1
- Saint Marys River1