Founded in February 22, 1917, Carter County is one of 56 counties in the state of Montana. Historically, Carter County was formed from Fallon County. The city of Ekalaka is the county seat. With FIPS code of 11, Carter County has a population of 1,428 and area of 3,340 square miles (8,651 km2).
List of all cities in Carter County, MT alphabetically
| City/Town | Postal Code | Area Code |
| Alzada, MT | 59311 | 406 |
| Boyes, MT | 59316 | 406 |
| Capitol, MT | 59319 | 406 |
| Ekalaka, MT | 59324 | 406 |
| Hammond, MT | 59332 | 406 |
| Mill Iron, MT | 59324 | 406 |