Railroad Archives Online
| Places term | Scope note | Archival description count | Authority record count |
|---|---|---|---|
| Oneida (Iowa) | 0 | 0 | |
| O'Neill (Neb.) | 5 | 0 | |
| Onion Creek (Wash.) | 2 | 0 | |
| Ononadaga Mine (Minn.) | 0 | 0 | |
| Onondaga Mine (Minn.) | 11 | 0 | |
| Onslow (Wash.) | 2 | 0 | |
| Ontario (5) | 0 | 0 | |
| Ontarioville (Ill.) | 0 | 0 | |
| Ontonagon (Mich.) | 0 | 0 | |
| Oolitic (Ind.) | 0 | 0 |