Sullivan County, New Hampshire

Sullivan County is a county in New Hampshire, United States, on the Vermont border along the Connecticut River. It had a population of 43,063 at the 2020 census and covers 552 square miles (1,430 km2) centred near 43°22′N 72°13′W.

Newport is the county seat, and its postal code is 03773. The county has one city (Claremont) and 13 towns, plus a scatter of unincorporated villages inside those towns — no separate townships, since New Hampshire counties are divided directly into towns rather than civil townships. Sullivan County runs on Eastern time and is the second-least populous county in New Hampshire.

Towns & Villages in Sullivan County

Sullivan County has 14 incorporated municipalities: Claremont, its largest community, is chartered as a city; the rest are New England towns, the standard form of local government here. Below them are a handful of older, unincorporated village names — postal or mill-era settlements with no government of their own, listed by the town that contains them. Population figures are the 2020 census; a dash means no separate count exists for that place.

Several of these towns contain older village clusters that appear on maps but are not separately governed or counted: Meriden and East Plainfield (in Plainfield), Georges Mills and Sunapee Harbor (in Sunapee), Guild and Kelleyville (in Newport), West Claremont (in Claremont), North Charlestown (in Charlestown), South Acworth and East Acworth (in Acworth), and Cornish Flat, Cornish Center and Cornish Mills (in Cornish, which has never had a single dominant village center). These carry no independent population count and are not municipalities.

ZIP Codes

• 03601 — Acworth
• 03603 — Charlestown
• 03743 — Claremont
• 03745 — Cornish
• 03746 — Cornish Flat
• 03752 — Goshen
• 03753 — Grantham
• 03605 — Lempster
• 03770 — Meriden (village in Plainfield, home of Kimball Union Academy)
• 03773 — Newport
• 03781 — Plainfield
• 03284 — Springfield
• 03782 — Sunapee
• 03280 — Washington

Croydon, Langdon and Unity have no post office of their own; mail there is addressed through neighboring Newport, Charlestown or Claremont ZIPs.

Geography

Sullivan County sits in west-central New Hampshire along the Connecticut River, which forms its entire western boundary with Vermont. The land rises from the river valley into rolling, forested hill country, with Mount Sunapee (2,743 feet) and Lake Sunapee, a major recreation destination, in the county’s northeast corner. About 3 percent of the county is water. The county borders Grafton County to the north, Merrimack County to the east, Hillsborough County to the southeast, Cheshire County to the south, and Windsor County, Vermont and Windham County, Vermont across the river to the west.

Demographics

Sullivan County’s population was 43,063 at the 2020 census. Claremont, with 12,949 residents, is by far the largest community, followed by Newport with 6,299. Median household income in the county runs below the New Hampshire median of $96,838, a gap typical of the state’s rural counties away from the Boston commuter belt. Population density works out to roughly 80 people per square mile of land area, concentrated along the Route 12A/103 corridor between Claremont and Newport.

Economy & Local Life

Claremont and Newport anchor the county’s economy, with a mix of small manufacturing, health care and retail; Claremont’s mills once produced textiles and paper, and the city has worked to redevelop its old mill buildings along the Sugar River. Tourism around Lake Sunapee and Mount Sunapee Resort brings seasonal visitors and second-home owners to the eastern towns. Colby-Sawyer College sits just across the county line in New London, and Kimball Union Academy, a boarding school founded in 1813, is based in Meriden village in Plainfield. Farming persists on a smaller scale in Unity, Croydon and Acworth.

History

Sullivan County was created in 1827, split from the northern part of Cheshire County with Newport as its seat. It is named for John Sullivan (1740–1795), a New Hampshire major general in the Revolutionary War who later served as the state’s chief executive. The Saint-Gaudens National Historic Site in Cornish preserves the home and studio of sculptor Augustus Saint-Gaudens, the center of an artists’ colony that gathered there in the late 19th and early 20th centuries. Sullivan County has also drawn attention as a presidential-election bellwether, having backed the eventual national winner in most elections since 1964.

Getting There

Interstate 91 runs along the Vermont side of the river, reachable via bridges at Charlestown and Claremont, while NH Route 12 and Route 103 are the main county roads linking Claremont, Newport and Sunapee.

• Concord — 40 miles east
• Manchester — 55 miles southeast
• White River Junction, VT — 25 miles northwest
• Keene — 30 miles south

The nearest commercial airport is Manchester-Boston Regional Airport, about an hour’s drive southeast.

Frequently Asked Questions

Where is Sullivan County, New Hampshire?
It is in west-central New Hampshire, bordering Vermont along the Connecticut River, between Grafton and Cheshire counties.

What is the population of Sullivan County?
43,063 people, as of the 2020 census.

How big is Sullivan County?
552 square miles (1,430 km2), of which about 15 square miles is water.

What is the county seat of Sullivan County?
Newport.

How many towns are in Sullivan County?
14 municipalities — one city, Claremont, and 13 towns.

What ZIP codes are in Sullivan County?
Fourteen, from 03280 (Washington) to 03782 (Sunapee); Newport uses 03773 and Claremont uses 03743.

What is Sullivan County known for?
Lake Sunapee and Mount Sunapee Resort, and the Saint-Gaudens National Historic Site in Cornish.

More counties in this state: Towns and villages in New Hampshire.