Coos County, located in the northernmost part of New Hampshire, is a region of rugged mountains, dense forests, and pristine waterways. From its majestic peaks to its tranquil lakes and rivers, Coos County offers a diverse array of geographical features and natural beauty that define its environment and shape its identity.


According to Clothesbliss, Coos County spans approximately 1,801 square miles (4,662 square kilometers) in northern New Hampshire, making it the largest county in the state by land area. It is bordered by several other counties, including Grafton County to the south, Carroll County to the southeast, and Oxford County in Maine to the east. The county’s landscape is primarily characterized by the White Mountains in the eastern part and the Connecticut River Valley in the west.

The White Mountains, part of the northern Appalachian Mountains, dominate the eastern part of Coos County, with rugged peaks, deep valleys, and dense forests. Mount Washington, the highest peak in the northeastern United States, is located in Coos County and attracts thousands of hikers and outdoor enthusiasts each year.

In contrast, the western part of Coos County is characterized by rolling hills and fertile valleys, including the Connecticut River Valley, which forms the county’s western boundary. The Connecticut River, one of the longest rivers in New England, serves as a vital transportation corridor and natural resource for the region.


Coos County experiences a humid continental climate with four distinct seasons. Summers are typically mild and pleasant, with average high temperatures in the 70s to 80s°F (21-27°C) and low humidity levels. Nights can be cool, especially at higher elevations, making for comfortable sleeping weather.

Winters in Coos County are cold and snowy, with average high temperatures in the 20s to 30s°F (-6 to -1°C) and lows often dropping below freezing. Snowfall is abundant in the White Mountains, with annual snowfall totals averaging around 100 to 150 inches (254 to 381 centimeters) in higher elevations.

Spring and fall are transitional seasons characterized by mild temperatures and fluctuating weather patterns. Spring brings blooming wildflowers and the return of migratory birds, while fall brings vibrant foliage and the onset of winter weather.

Rivers and Lakes:

Coos County is blessed with numerous rivers, lakes, and streams, providing abundant recreational opportunities for residents and visitors alike. Some of the notable rivers and lakes in Coos County include:

  1. Connecticut River: The Connecticut River forms the western boundary of Coos County, offering opportunities for fishing, boating, and wildlife viewing. The river is known for its scenic beauty and diverse aquatic habitat, including trout, bass, and other game fish.
  2. Androscoggin River: The Androscoggin River flows through the eastern part of Coos County, offering opportunities for fishing, canoeing, and kayaking. The river is known for its clear water and rugged scenery, with access to hiking trails and camping areas.
  3. Lake Umbagog: Lake Umbagog, located on the border between New Hampshire and Maine, is a popular destination for fishing, boating, and wildlife viewing. The lake is known for its pristine waters and abundant wildlife, including loons, eagles, and moose.

In addition to its larger rivers and lakes, Coos County is also home to numerous smaller streams and ponds, providing additional opportunities for fishing, swimming, and picnicking.

Vegetation and Wildlife:

Coos County’s diverse habitats support a rich diversity of vegetation and wildlife. The county is home to hardwood forests, coniferous forests, wetlands, and alpine meadows, providing habitat for a variety of plant and animal species.

Common tree species found in Coos County include maple, birch, pine, spruce, and fir. These forests provide habitat for deer, moose, black bear, bobcat, and a variety of bird species, including songbirds, raptors, and waterfowl.

In addition to terrestrial wildlife, Coos County’s rivers and lakes support a diverse fishery, with popular game fish including trout, salmon, bass, and pickerel. The county’s waterways also provide habitat for otters, beavers, muskrats, and other aquatic species.

Communities and Economy:

Coos County is home to several small towns and communities, each offering its own unique blend of rural charm and outdoor recreation. The county seat and largest town is Lancaster, known for its historic downtown district, cultural attractions, and outdoor amenities.

Other communities in Coos County include Berlin, Gorham, Colebrook, and Pittsburg, each with its own distinct character and sense of community. These towns serve as centers of commerce, education, and culture for residents of the surrounding area.

The economy of Coos County is diverse, with key sectors including tourism, outdoor recreation, forestry, and manufacturing. Tourism remains a significant driver of the local economy, with visitors drawn to the county’s natural beauty, recreational opportunities, and historic attractions.

Forestry is also an important industry in Coos County, with timber harvesting and wood products manufacturing providing employment opportunities and contributing to the local economy. Manufacturing sectors include paper mills, lumber mills, and small-scale artisanal producers.


In summary, Coos County, New Hampshire, is a region of natural beauty, outdoor adventure, and rural charm. From its rugged mountains and clear streams to its historic towns and cultural attractions, Coos County offers a unique blend of geographical features and cultural heritage that make it a special place to live and visit. With its rich natural resources, diverse wildlife habitats, and strong sense of community, Coos County remains a treasured destination in northern New Hampshire.