Merrimack
Merrimack is a mapped river in the YearMaps hydrographic index. River courses organise settlement, agriculture and frontier-making more durably than any political boundary, and this reach is indexed against the dams, lakes and cities within its catchment.
- Feature Class
- River
- Coordinates
- 43.24°, -71.52°
About Merrimack
The Merrimack River (or Merrimac River, an occasional earlier spelling) is a 117-mile-long (188 km) river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Massachusetts, and then flows northeast until it empties into the Gulf of Maine at Newburyport. From Pawtucket Falls in Lowell, Massachusetts, onward, the Massachusetts–New Hampshire border is roughly calculated as the line three miles north of the river.
The Merrimack is an important regional focus in both New Hampshire and Massachusetts. The central-southern part of New Hampshire and most of northeast Massachusetts is known as the Merrimack Valley.
Several U.S. naval ships have been named USS Merrimack and USS Merrimac in honor of this river. The river is also known for the early American literary classic A Week on the Concord and Merrimack Rivers by Henry David Thoreau.
Encyclopedic summary adapted from Wikipedia: Merrimack River (CC BY-SA 4.0).
Merrimack in Depth
Geography
The Merrimack River watershed covers 5,010 square miles (12,980 km2) in southern New Hampshire and northeastern Massachusetts. It is the fourth largest river basin in New England.
The river begins in the city of Franklin, New Hampshire, at the confluence of the Pemigewasset and Winnipesaukee rivers. From there, the river flows south through Concord, Manchester, and Nashua, entering Massachusetts at the town of Tyngsborough, where it turns northeast and winds past or through Chelmsford, Lowell, Dracut, Tewksbury, Andover, Methuen, Lawrence, North Andover, Haverhill, Groveland, West Newbury, Merrimac, and Amesbury, to its mouth at the Gulf of Maine between the city of Newburyport and the town of Salisbury.
History
Prior to glaciation, the Merrimack continued its southward course far beyond the present day New Hampshire-Massachusetts border to enter the Gulf of Maine near Boston. Upon the glacier's retreat around 14,000 years ago, debris deposited north of Boston filled the lower Merrimack Valley, redirecting the river into its current northeast bend at Lowell. The Neville archaeological site is located along the river's banks in New Hampshire.
On the Merrimack River's banks are a number of cities built to take advantage of water power in the 19th century, when textile mills dominated the New England economy: Concord, Manchester, and Nashua in New Hampshire, and Lowell, Lawrence, and Haverhill in Massachusetts. At the mouth of the river is the small city of Newburyport.
Sections adapted from Wikipedia: Merrimack River (CC BY-SA 4.0).
Merrimack: Key Facts
| Length | 177 km |
|---|---|
| Average discharge | 214 m³/s |
| Drainage basin | 12,951 km² |
| Source | Pemigewasset River |
| Mouth | Gulf of Maine |
| Drainage system | Merrimack River watershed |
| Tributaries | Contoocook River, Souhegan River, Nashua River, Concord River, Shawsheen River, Pemigewasset River, Winnipesaukee River, Beaver Brook |
Facts from Wikidata Q517787 (CC0).
Major River Dossiers
Hand-written studies of the great river systems of history.
Connected Reaches
Nearby watercourses in the same drainage network.
Water Bodies in the Catchment
Settlements Along the Reach
Hydraulic Infrastructure Nearby
Surrounding Terrain
Merrimack: Quick Answers
- Where is Merrimack?
- Merrimack is located in United States, at 43.2365° N, 71.5210° W.
- Are there dams on the Merrimack?
- No dam on the Merrimack is recorded in the YearMaps dam index, which covers major structures only.