| 1 | SWSX | Street's Western Stable-Car Line (Streets Co., Inc.) | 8/1920-7/1923 | | NAKINA |
| 2 | SWSX | The Streets Co., series 625001-626500 & 627526-627500 (Penna. R.R. System) | 8/1920-7/1923 | | NAKINA |
| 3 | SWSX | *PENNSYLVANIA RAILROAD [STREETS CO., INC.; STREET'S WESTERN STABLE-CAR LINE] | | | PWRC |
| 4 | SWSX | *STILLWATER & ST. PAUL RAILROAD | | | PWRC |
| 5 | SWSX | +SUPERIOR WELL SERVICES, INC. | | | PWRC |
| 6 | SWSX | SUPERIOR WELL SERVICES INC | | | SCAC4 |
