The Merrimack River, formed by the confluence of the Pemigewasset River (left) and Winnipesaukee River (right) is shown on a map of the northeastern United States

The Merrimack River (or Merrimac River, an earlier spelling that is sometimes still used) is a 110-mile-long (177-kilometer-long) river in the Northeastern United States. It rises in central New Hampshire at the confluence of the Pemigewasset and Winnipesaukee rivers, flows southward into Massachusetts, and then flows northeast, near the Massachusetts-New Hampshire border, until it empties into the Atlantic Ocean at Newburyport.

Several U.S. naval ships have been named the USS Merrimack and USS Merrimac in honor of this river.

Prior to glaciation, the Merrimack continued its southward course far beyond the present day New Hampshire-Massachusetts border to enter the Atlantic Ocean near Boston. Upon the glacier's retreat, debris deposited north of Boston filled the lower Merrimack Valley, redirecting the river into its current northeast bend at Lowell.

The total watershed of the river is approximately 5,000 square miles (13,000 km²), covering much of southern New Hampshire and a portion of northeastern Massachusetts. On its 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 (the state capital), Manchester, and Nashua in New Hampshire, and Lowell, Lawrence, and Haverhill in Massachusetts.

The river is perhaps best known for the early American literary classic A Week on the Concord and Merrimac River by Henry David Thoreau. Among its tributaries are the Souhegan River, which extends west from the town of Merrimack, New Hampshire, and the Concord River.

Etymology

The name Merrimack is believed to have been adopted by early European settlers from Merruasquamack, a name meaning "swift water place" that given by Native American tribes for the portion of the river between Manchester, New Hampshire and Lowell, Massachusetts. A number of tribes occupied the watershed and gave the river several different names.

The original Euro-American spelling of the river's name was Merrimac. West Amesbury, Massachusetts , a former part of Amesbury, Massachusetts, contained the village of Merrimacport; it later separated from Amesbury and was incorporated in 1876 as Merrimac, Massachusetts.

Amesbury was incorporated long before Merrimack, New Hampshire, which is also named for the river. Since Merrimack is closer to the source of the river, many assume that the river receives its name from this community; however, early maps and documents clearly refer to the river as the Merrimac. It is unclear when, where, and why the name was officially recognized as Merrimack.

See also

• List of Massachusetts rivers
• List of New Hampshire rivers

External link

• USGS Merrimack River drainage basin in Massachusetts
• Merrimack.org Merrimack River watershed in New Hampshire
• US Army Corps of Engineers Merrimack River basin reservoir and river level status
• Merrimack River Watershed Council, a non-profit conservation group based in Lowell, Mass.