| Code | Name | Region |
|---|---|---|
| USUOK | Roanoke | IN |
| USRNE | Roanoke | TX |
| USROA | Roanoke | VA |
| USRZZ | Roanoke Rapids | NC |
| USR84 | Roaring Branch | PA |
| USIIR | Roaring River | NC |
| USRRS | Roaring Spring | PA |
| USRBA | Robards | KY |
| USRO7 | Robbins | CA |
| USRBS | Robbins | NC |
| USRB7 | Robbinsdale | MN |
| US9RO | Robbinston | ME |
| USRBB | Robbinsville | NC |
| USRBV | Robbinsville | NJ |
| USRE3 | Robeline | LA |
| USR9S | Riverside | LA |
| USRVM | Riverside | MI |
| USYRS | Riverside | MO |
| USRSD | Riverside | NJ |
| USOH4 | Riverside | OH |
| USRI7 | Riverside | PA |
| USVSE | Riverside | RI |
| USRN7 | Riverton | IL |
| USRJE | Riverton | KS |
| USRV6 | Riverton | MN |
| USRVJ | Riverton | NJ |
| USYIV | Riverton | UT |
| USRIW | Riverton | WY |
| USRRW | Riverview | FL |
| USRVW | Riverview | MI |
| USRL9 | Riverville | VA |
| USVWD | Riverwoods | IL |
| USIEJ | Rives Junction | MI |
| USRBC | Riviera Beach | FL |
| USVYX | Rixeyville | VA |
| USQQN | River Ridge | LA |
| USRRJ | River Rouge | MI |
| USRR8 | Rivera Beach | FL |
| USZRB | Riverbank | CA |
| USRVX | Riverdale | CA |
| USRQV | Riverdale | GA |
| USIVU | Riverdale | IA |
| USRRD | Riverdale | IL |
| USRVL | Riverdale | MD |
| USRXE | Riverdale | MI |
| USRDL | Riverdale | NJ |
| USRV5 | Riverdale | NY |
| USRD9 | Riverdale | UT |
| USRGJ | Rivergate | OR |
| USRHD | Riverhead | NY |