| 1 | OZKF | OZARK FORWARDING CO | | | SCAC3 |
| 2 | OZKF | OZARK FORWARDING INC | | | SCAC4 |
| 3 | OZKM | OZARK TRANSMODAL | | | SCAC4 |
| 4 | OZKV | OZARK VAN LINES INC | | | SCAC4 |
| 5 | OZKX | Union Tank Car Co. | added 7/1962; 7/1965-4/1970; eliminated 7/1973 | | NAKINA |
| 6 | OZKX | Ozark Tank Car Co. | 1/1952-4/1961; eliminated 7/1962 | | NAKINA |
| 7 | OZKX | Deep Rock Oil Corp. | 7/1937-1/1950 | | NAKINA |
| 8 | OZKX | Ozark Car Corp. | 7/1932 | | NAKINA |
| 9 | OZKX | Ozark Car Corp. (Deep Rock Oil Corp.) | 7/1935 | | NAKINA |
| 10 | OZKX | Ozark Car Corp. (Deep Rock Oil Corp.) | Apr-38 | | NRHS |
| 11 | OZKX | Ozark Tank Car Co. | 1/52-4/61 | | NRHS |
| 12 | OZKX | Union Tank Car Co. | 7/65-4/70; eliminated 7/73 | | NRHS |
| 13 | OZKX | UNION TANK CAR CO. [OZARK TANK CAR CO.; DEEP ROCK OIL CORP.; OZARK CAR CO.] | | | PWRC |
