APA
| Apache Railway Company | 2 |
ARR
| Alaska Railroad | 24 |
ATSF
| Atchison Topeka & Santa Fe | 11 |
BCH
| Southern Railway of British Columbia Limited | 2 |
BCOL
| Canadian National Railways | 11 |
BM
| Boston & Maine | 1 |
BN
| Burlington Northern | 50 |
BNSF
| BNSF Railway | 89 |
BNX
| BNX | 1 |
BRC
| Belt Railway of Chicago | 1 |
CBQ
| Chicago Burlington & Quincy | 1 |
CBRY
| Copper Basin Railway | 2 |
CEI
| Chicago & Eastern Illinois | 2 |
CGW
| Chicago Great Western | 1 |
CN
| Canadian National Railways | 7 |
CNW
| Chicago & Northwestern | 7 |
CO
| Chesapeake & Ohio | 3 |
COP
| City of Prineville Railway | 3 |
CORP
| Central Oregon & Pacific | 7 |
CP
| Canadian Pacific Railway | 12 |
CSX
| CSX Railroad | 5 |
CW
| Colorado and Wyoming | 2 |
CWW
| CWW | 5 |
DMIR
| Duluth Missabe & Iron Range | 1 |
DRGW
| Denver & Rio Grande Western | 1 |
GN
| Great Northern | 9 |
GNX
| GNX | 1 |
HZGX
| Herzog Contracting Corporation | 16 |
ICG
| Illinois Central Gulf | 2 |
INPR
| Idaho Northern and Pacific Railroad | 1 |
LC
| Lancaster & Chester | 5 |
LINC
| Lewis and Clark Railway Company | 1 |
LMIX
| Loram Maintenance of Way Inc. | 4 |
LORA
| LORA | 1 |
MCR
| McCloud Railway Company | 1 |
MILW
| Milwaukee Road | 24 |
MP
| Missouri Pacific | 5 |
MRL
| Montana Rail Link | 11 |
NNYX
| National New York Central Railroad Museu | 2 |
NP
| Northern Pacific | 4 |
NYC
| New York Central | 1 |
PC
| Penn Central | 1 |
PGE
| Pacific Great Eastern | 1 |
PSAP
| Puget Sound and Pacific Railroad Company | 1 |
RMCX
| Reynolds Metals Company | 2 |
RTJX
| RTJX | 1 |
SI
| Union Pacific Railroad Company (Spokane International) | 3 |
SLSF
| Saint Louis-San Francisco | 1 |
SOO
| Soo Line | 5 |
SPMW
| Southern Pacific Maintenance of Way | 25 |
SPS
| Spokane Portland & Seattle | 2 |
SRGX
| SRGX | 1 |
SVRR
| Shamokin Valley Railroad Company | 1 |
TMBL
| Tacoma Municipal Belt Line Railway | 1 |
UP
| Union Pacific Railroad Company | 82 |
UPX
| UPX | 1 |
VT
| Virginia & Truckee | 2 |
WP
| Western Pacific | 1 |