| Code | Name | Region |
|---|---|---|
| US2RV | Riverside | AL |
| USRAL | Riverside | CA |
| USVRD | Riverside | CT |
| USVSD | Riverside | IA |
| USIVD | Riverside | IL |
| USRPL | Ripley | TN |
| USRPE | Ripley | WV |
| USRIP | Ripon | CA |
| USRPN | Ripon | WI |
| USRP4 | Ripplemead | VA |
| US7RI | Ripton | VT |
| USRIH | Ririe | ID |
| USR9C | Rising City | NE |
| USIWK | Rising Fawn | GA |
| USRUN | Rising Sun | MD |
| USRTN | Rittman | OH |
| USRZV | Ritzville | WA |
| USR6V | Riva | MD |
| USRQQ | River Edge | NJ |
| USRFL | River Falls | AL |
| USRFW | River Falls | WI |
| USRVO | River Forest | IL |
| USRG6 | River Grove | IL |
| USRIG | River Grove/chicago | IL |
| USR4V | River Hills | WI |
| USRGN | Ringtown | PA |
| USRIO | Ringwood | IL |
| USRIJ | Ringwood | NJ |
| USR3W | Ringwood | OK |
| USR88 | Rio | WI |
| USRB8 | Rio Blanco | CO |
| USDJL | Rio Dell | CA |
| USRGF | Rio Grande | NJ |
| USRE4 | Rio Grande | OH |
| USRGC | Rio Grande City | TX |
| USRH8 | Rio Hondo | TX |
| USRLI | Rio Linda | CA |
| USRO6 | Rio Oso | CA |
| USRRC | Rio Rancho | NM |
| USRRQ | Rio Rico | AZ |
| USRVA | Rio Vista | CA |
| USIAJ | Riparius | NY |
| USRPP | Ripley | CA |
| USRPM | Ripley | MS |
| USRP5 | Ripley | NY |
| USRQF | Rifton | NY |
| USIG8 | Riga | MI |
| USRG3 | Rigby | ID |
| USRG7 | Riggins | ID |
| USIEY | Riley | KS |