| Code | Name | Region |
|---|---|---|
| USOD6 | Columbus | ND |
| USOLU | Columbus | NE |
| USYBC | Columbus | NJ |
| USCUS | Columbus | NM |
| USCMH | Columbus | OH |
| USVCB | Columbus | TX |
| USCBW | Columbus | WI |
| USL9M | Columbus City | IA |
| USCGQ | Columbus Grove | OH |
| USCQB | Columbus Junction | IA |
| USCQC | Colusa | CA |
| USC3V | Colver | PA |
| USVE8 | Colville | WA |
| USCWO | Colwich | KS |
| US9CW | Colwyn | PA |
| USCMJ | Comanche | OK |
| USCMC | Comanche | TX |
| USOMS | Combes | TX |
| USXDM | Combined Locks | WI |
| USCAJ | Columbia City | IN |
| US8OL | Columbia City | OR |
| USICD | Columbia Cross Roads | PA |
| USCF9 | Columbia Falls | ME |
| USYCU | Columbia Falls | MT |
| USUBQ | Columbia Heights | MN |
| USCAF | Columbia Station | OH |
| USUMI | Columbiana | AL |
| USCOG | Columbiana | OH |
| USUVM | Columbiaville | MI |
| USCSG | Columbus | GA |
| USCB9 | Columbus | IL |
| USCLU | Columbus | IN |
| USUCU | Columbus | KS |
| USUQM | Columbus | KY |
| USVDA | Columbus | MI |
| USOB6 | Columbus | MN |
| USOLP | Columbus | MO |
| USUBS | Columbus | MS |
| USCB8 | Columbus | MT |
| USRTO | Colton | CA |
| USZXX | Colton | OR |
| USCTN | Colts Neck | NJ |
| USCOZ | Columbia | AL |
| USCOA | Columbia | CA |
| USCX2 | Columbia | CT |
| USCL6 | Columbia | IL |
| USQOU | Columbia | KY |
| USC72 | Columbia | LA |
| USACW | Columbia | MD |
| USCOU | Columbia | MO |