BCOL
| Canadian National Railways | 2 |
BO
| Baltimore & Ohio | 1 |
CN
| Canadian National Railways | 10 |
CR
| Conrail | 1 |
DRGW
| Denver & Rio Grande Western | 1 |
MP
| Missouri Pacific | 3 |
NS
| Norfolk Southern | 1 |
NYC
| New York Central | 1 |
SOU
| Southern | 2 |
SPMW
| Southern Pacific Maintenance of Way | 1 |