ARR
| Alaska Railroad | 5 |
BN
| Burlington Northern | 17 |
BNSF
| BNSF Railway | 4 |
CN
| Canadian National Railways | 1 |
ELS
| Escanaba and Lake Superior Railroad Comp | 4 |
GN
| Great Northern | 1 |
MILW
| Milwaukee Road | 17 |
MILX
| General Electric Rail Services | 1 |
RI
| RI | 2 |
SPMW
| Southern Pacific Maintenance of Way | 6 |
UP
| Union Pacific Railroad Company | 6 |