AOK
| Arkansas-Oklahoma Railroad | 1 |
BNSF
| BNSF Railway | 1 |
DRGW
| Denver & Rio Grande Western | 1 |
HZGX
| Herzog Contracting Corporation | 14 |
MWAX
| Martin Marietta Materials Incorporated | 1 |
SOXX
| SMBC RAIL SERVICES LLC | 9 |
SP
| Southern Pacific | 1 |
SREX
| StatesRail Equipment Company LLC | 7 |
UP
| Union Pacific Railroad Company | 4 |