| Clue | Source | Date |
|---|---|---|
| Quaker State's early headquarters | Newsday | 19 Oct 2024 |
| Pennsylvania petroleum center, once | New York Times | 11 Aug 2021 |
| Original Pennsylvania headquarters of Quaker State | The Washington Post | 08 Nov 2018 |
| Original Pennsylvania headquarters of Quaker State | LA Times Daily | 08 Nov 2018 |
| Original Pennsylvania headquarters of Quaker State | ||
| Quaker State's early headquarters | ||
| Place on the Allegheny River. |