ATSF
| Atchison Topeka & Santa Fe | 1 |
AZER
| Arizona Eastern Railway Company | 2 |
BN
| Burlington Northern | 3 |
CNW
| Chicago & Northwestern | 3 |
DRGX
| Denver and Royal Gorge Railway LLC | 1 |
HZGX
| Herzog Contracting Corporation | 1 |
MP
| Missouri Pacific | 1 |
SP
| Southern Pacific | 1 |
SPMW
| Southern Pacific Maintenance of Way | 1 |
UP
| Union Pacific Railroad Company | 2 |
WSOR
| Wisconsin & Southern | 3 |
WSSX
| Wedron Silica Company | 1 |