| 1 | WTR | Wrightsville and Tennille R.R. Co. | 4/1938-4/1970 | | NAKINA |
| 2 | WTR | Wrightsville and Tennille R.R. Co. | 4/38-4/70 | | NRHS |
| 3 | WTR | *WHIPPANY TOONERVILLE RAILROAD | | | PWRC |
| 4 | WTR | *WEST TEXAS AND LUBBOCK RAILROAD CO. | | | PWRC |
| 5 | WTRA | WATSONORA TRANSPORT | | | SCAC4 |
| 6 | WTRB | WEBB TRUCKING | | | SCAC4 |
| 7 | WTRC | WESTERN TRUCKING CO | | | PWRC |
| 8 | WTRE | WEST TENNESSEE RECYCLING CO LLC | | | SCAC4 |
| 9 | WTRI | WETHERED TRANSPORT INC | | | SCAC4 |
| 10 | WTRJ | WATERS, JAY, INC | | | SCAC1 |
| 11 | WTRJ | WILLIAMS TRUCKING | | | SCAC4 |
| 12 | WTRK | WARD TRUCKING CO | | | SCAC4 |
| 13 | WTRL | WILSONS TRUCKING | | | SCAC4 |
| 14 | WTRM | The Warren & Trumball R.R. Co. | added 7/1994; 7/2000-7/2005 | | NAKINA |
| 15 | WTRM | The Warren & Trumball R.R. Co. | added 7/94; 7/2000 | | NRHS |
| 16 | WTRM | WARREN & TRUMBULL RAILROAD COMPANY | | | PWRC |
| 17 | WTRM | Warren and Trumbull Railroad | | | RSRV |
| 18 | WTRM | WARREN & TRUMBULL RAILROAD COMPANY, | | | SCAC4 |
| 19 | WTRO | WHITSON TRUCKING | | | SCAC4 |
| 20 | WTRU | WESTRAFO S.R.L. | | I | BIC |
| 21 | WTRV | WATERVILLE EXPRESS | | | SCAC1 |
| 22 | WTRV | WEAVER TRUCKING | | | SCAC4 |
| 23 | WTRW | WORLDTRANS INTERNATIONAL | | | SCAC4 |
| 24 | WTRY | Wilmington Terminal R.R., Inc. | added 1/1987; 1/1994-7/2000; eliminated 4/2003; 7/2005 | | NAKINA |
| 25 | WTRY | Wilmington Terminal R.R., Inc. | added 1/87; 1/94-7/2000 | | NRHS |
| 26 | WTRY | WILMINGTON TERMINAL RAILROAD, INC. | | | PWRC |
| 27 | WTRY | Wilmington Terminal Railroad | | | RSRV |
