Matanuska-Susitna Borough is a borough in Alaska, United States, taking in the full watersheds of the Matanuska and Susitna Rivers north of Cook Inlet. It had a population of 107,081 at the 2020 census and covers 25,258 square miles (65,420 km2) of land and water, centred near 62°24′N 149°35′W.<\/p>\n
Palmer is the county seat and its postal code is 99645. The borough has 3 incorporated cities and about two dozen unincorporated communities and CDPs, sits in the Alaska Standard Time zone (UTC−9, UTC−8 daylight), and is part of the Anchorage metropolitan statistical area.<\/p>\n
The borough’s population is spread across 3 incorporated cities and roughly two dozen unincorporated communities and census-designated places (CDPs). Alaska has no county subdivisions below the borough, so every place below is either a city or a CDP; population figures are 2020 census counts where verified, otherwise shown as —.<\/p>\n
| Place<\/th>\n | Type<\/th>\n | Pop.<\/th>\n | ZIP<\/th>\n<\/tr>\n |
|---|---|---|---|
| Palmer<\/td>\n | City · seat<\/td>\n | 5,888<\/td>\n | 99645<\/td>\n<\/tr>\n |
| Wasilla<\/td>\n | City<\/td>\n | 9,054<\/td>\n | 99654<\/td>\n<\/tr>\n |
| Houston<\/td>\n | City<\/td>\n | —<\/td>\n | 99694<\/td>\n<\/tr>\n |
| Knik-Fairview<\/td>\n | CDP<\/td>\n | 19,297<\/td>\n | 99654<\/td>\n<\/tr>\n |
| Big Lake<\/td>\n | CDP<\/td>\n | —<\/td>\n | 99652<\/td>\n<\/tr>\n |
| Sutton-Alpine<\/td>\n | CDP<\/td>\n | —<\/td>\n | 99674<\/td>\n<\/tr>\n |
| Talkeetna<\/td>\n | CDP<\/td>\n | —<\/td>\n | 99676<\/td>\n<\/tr>\n |
| Trapper Creek<\/td>\n | CDP<\/td>\n | —<\/td>\n | 99683<\/td>\n<\/tr>\n |
| Willow<\/td>\n | CDP<\/td>\n | —<\/td>\n | 99688<\/td>\n<\/tr>\n<\/table>\n<\/div>\n Knik-Fairview is unincorporated but, at 19,297 residents, is Alaska’s most populous CDP statewide — more populous than either Palmer or Houston. Sutton is often written jointly with neighboring Alpine as the CDP “Sutton-Alpine.”<\/p>\n ZIP Codes<\/h2>\nSeveral small, road-inaccessible communities in the borough’s north share the Talkeetna or Trapper Creek post offices rather than holding their own ZIP code.<\/p>\n Geography<\/h2>\nThe Mat-Su Borough spans the broad Matanuska-Susitna Valley, from the glaciated peaks of the Talkeetna and Chugach Mountains down to the tidal flats of upper Cook Inlet. The Matanuska and Susitna Rivers, both fed by glaciers, drain the borough and give it its name; the fertile valley floor around Palmer supports one of Alaska’s few significant farming districts, a legacy of the 1935 New Deal colony that settled it.<\/p>\n |