AOK
| Arkansas-Oklahoma Railroad | 7 |
APA
| Apache Railway Company | 1 |
ARR
| Alaska Railroad | 79 |
ATSF
| Atchison Topeka & Santa Fe | 8 |
AWXX
| East Carbon development Company | 1 |
BLPX
| BLPX | 2 |
BN
| Burlington Northern | 7 |
BNSF
| BNSF Railway | 62 |
BO
| Baltimore & Ohio | 1 |
BTCX
| Browner Turnout Company | 1 |
CCKX
| CCKX Incorporated | 1 |
COER
| Crab Orchard & Egyptian | 1 |
COP
| City of Prineville Railway | 1 |
CP
| Canadian Pacific Railway | 1 |
CR
| Conrail | 1 |
CRLE
| Coe Rail Incorporated | 2 |
CW
| Colorado and Wyoming | 3 |
CWMX
| Chemical Waste Management Incorporated | 4 |
DMIR
| Duluth Missabe & Iron Range | 1 |
DODX
| Department Of Defense | 23 |
DRGW
| Denver & Rio Grande Western | 6 |
ELS
| Escanaba and Lake Superior Railroad Comp | 1 |
FEC
| Florida East Coast | 1 |
GMO
| Gulf Mobile & Ohio | 1 |
HESX
| Heritage Environmental Services | 1 |
HTTX
| TTX Company | 8 |
INPR
| Idaho Northern and Pacific Railroad | 1 |
ITTX
| TTX Company | 3 |
KRL
| Kasgro Rail Lines | 4 |
KTTX
| TTX Company | 1 |
LTTX
| TTX Company | 5 |
MILW
| Milwaukee Road | 6 |
MP
| Missouri Pacific | 5 |
MRL
| Montana Rail Link | 4 |
MTTX
| TTX Company | 16 |
NP
| Northern Pacific | 2 |
OTTX
| TTX Company | 8 |
POTB
| Port of Tillamook Bay | 3 |
POVA
| Pend Oreille Valley Railroad | 1 |
PTTX
| TTX Company | 3 |
QTTX
| TTX Company | 2 |
RTTX
| TTX Company | 2 |
SOXX
| SMBC RAIL SERVICES LLC | 3 |
SP
| Southern Pacific | 5 |
SPMW
| Southern Pacific Maintenance of Way | 9 |
SSW
| St Louis Southwestern (Cotton Belt) | 3 |
STMA
| St. Maries River Railroad Company | 1 |
SVRY
| SVRY | 1 |
TBCX
| Boeing Company | 10 |
TTAX
| TTX Company - Spine Cars | 2 |
TTBX
| TTX Company | 1 |
TTCX
| TTX Company | 1 |
TTEX
| TTX Company - Articulated Flat Cars (TOFC/COFC) | 1 |
TTHX
| TTX Company - Flat Cars | 1 |
TTMX
| TTX Company | 3 |
TTWX
| TTX Company | 2 |
TTX
| TTX Company | 1 |
UP
| Union Pacific Railroad Company | 12 |
WC
| Wisconsin Central | 1 |
WCRC
| Washington Central | 1 |
WICT
| Wisconsin & Calumet | 1 |
WPYR
| White Pass & Yukon Route | 2 |
WTTX
| TTX Company | 1 |