| 1 | WMX | Western Meat Co. | 8/1920-7/1923 | | NAKINA |
| 2 | WMX | Westmoreland Coal Co. | added 11/1934; 7/1937-1/1945; 1/1946 (not listed) | | NAKINA |
| 3 | WMX | Westmoreland Coal Co. | Apr-38 | | NRHS |
| 4 | WMX | WESTMORELAND COAL CO. | | | PWRC |
| 5 | WMXG | WMX LOGISTICS INC | | | SCAC4 |
| 6 | WMXN | WILLIAMS, D C TRANSPORTATION LLC | | | SCAC4 |
| 7 | WMXO | WILLIAMS TRANSPORT | | | SCAC4 |
| 8 | WMXP | WATROUS MOTOR EXPRESS, INC | | | SCAC1 |
| 9 | WMXS | WESTERN MARITIME EXPRESS INC | | | SCAC4 |
| 10 | WMXT | WALTZ, MAX TRUCKING | | | SCAC4 |
