| Code | Name | Region |
|---|---|---|
| USMPL | Mount Pleasant | TN |
| USMPS | Mount Pleasant | TX |
| USMSD | Mount Pleasant | UT |
| USUPN | Mount Pleasant | WI |
| USUPI | Mount Pleasant Mills | PA |
| USUPA | Mount Pleasant, Cabarrus | NC |
| USMPO | Mount Pocono | PA |
| USUQS | Mount Holly | SC |
| US7MH | Mount Holly | VT |
| USQHS | Mount Holly Springs | PA |
| USUHE | Mount Hope | AL |
| USM7H | Mount Hope | KS |
| USMH9 | Mount Hope | OH |
| USULZ | Mount Hope | WV |
| USMH4 | Mount Horeb | WI |
| USUIA | Mount Ida | AR |
| USUQV | Mount Jackson | VA |
| USOJW | Mount Jewett | PA |
| USMJ2 | Mount Joy | PA |
| USMJY | Mount Joy | PA |
| USMJB | Mount Juliet | TN |
| USMKS | Mount Kisco | NY |
| USLUJ | Mount Laurel | NJ |
| USMCL | Mount Mckinley | AK |
| USOUM | Mount Meigs | AL |
| USMXR | Mount Morris | IL |
| USMMB | Mount Morris | MI |
| USTBK | Mount Braddock | PA |
| USMC6 | Mount Carmel | IL |
| USMTK | Mount Carmel | PA |
| USKRL | Mount Carroll | IL |
| USMTC | Mount Clemens | MI |
| USMWR | Mount Crawford | VA |
| USDZT | Mount Desert | ME |
| USMUD | Mount Dora | FL |
| USME2 | Mount Eaton | OH |
| USM3E | Mount Eden | KY |
| USIUE | Mount Erie | IL |
| USM3F | Mount Freedom | NJ |
| USMGQ | Mount Gilead | NC |
| USUGO | Mount Gilead | OH |
| USM5G | Mount Gretna | PA |
| USTBO | Mount Hebron | MD |
| USNHR | Mount Hermon | CA |
| USMH6 | Mount Holly | AR |
| USMHX | Mount Holly | NC |
| USLLY | Mount Holly | NJ |
| US4MC | Mound City | IL |
| USM9C | Mound City | MO |
| USXZS | Mound House | NV |