Coös County
Also known as Coös County, New Hampshire, Coos County, Coos County, New Hampshire, Coös County, NH, Coos County, NH
county in New Hampshire, United States
Key facts
- Country
- United States
- State
- New Hampshire
- Named after
- Algonquian for “small pines”
- Seat
- Lancaster
- Largest city
- Berlin
- Total
- 1,830.3 sq mi (4,740 km )
- Land
- 1,794.6 sq mi (4,648 km )
- Water
- 35.7 sq mi (92 km ) 1.95%
- Estimate 2025
- 31,343
- Density
- 17.4/sq mi (6.7/km )
- Time zone
- UTC−5 ( Eastern )
- Summer dst
- UTC−4 ( EDT )
- Congressional district
Article
Coös County or Coos County (/ˈkoʊ.ɒs/, with two syllables) is the northernmost county in the U.S. state of New Hampshire. As of the 2020 census, the population was 31,268, making it the least-populated county in the state. The county seat is Lancaster.
Coös County is part of the Berlin, NH–VT Micropolitan Statistical Area. It is the only New Hampshire county on the Canada–United States border, south of the province of Quebec, and thus is home to New Hampshire's only international port of entry, the Pittsburg–Chartierville Border Crossing. The only city in Coös County is Berlin, with the rest of the communities being towns, or unincorporated townships, gores and grants.
Gallery (4)
On the map
2 mapped locations