Matanuska-Susitna Borough, Alaska
| Matanuska-Susitna Borough | |
|---|---|
| Location within the U.S. state of Alaska | |
| Alaska's location within the U.S. | |
| Coordinates: 62°24′N 149°35′W / 62.4°N 149.58°W | |
| Country | United States | 
| State | Alaska | 
| Incorporated | January 1, 1964 | 
| Named after | Matanuska River and Susitna River | 
| Seat | Palmer | 
| Largest CDP | Knik-Fairview | 
| Government | |
| • Borough Mayor | Edna DeVries | 
| Area | |
|  • Total | 25,258 sq mi (65,420 km2) | 
| • Land | 24,608 sq mi (63,730 km2) | 
| • Water | 650 sq mi (1,700 km2) 2.6% | 
| Population  (2020) | |
|  • Total | 107,081 | 
|  • Estimate  (2024) | 117,613 | 
| • Density | 4.2/sq mi (1.6/km2) | 
| Time zone | UTC−9 (Alaska) | 
| • Summer (DST) | UTC−8 (ADT) | 
| Congressional district | At-large | 
| Website | www | 
Matanuska-Susitna Borough (often referred to as the Mat-Su Borough) is a borough located in the U.S. state of Alaska. Its borough seat is Palmer, and the largest community is the census-designated place of Knik-Fairview. As of the 2020 census, the borough's population was 107,081.
The borough is part of the Anchorage Metropolitan Statistical Area, along with the municipality of Anchorage on its south.
The Mat-Su Borough is so designated because it contains the entire Matanuska and Susitna Rivers. They empty into Cook Inlet, which is the southern border of the Mat-Su Borough. It is one of the few agricultural areas of Alaska.