Bear Brook is a 10 miles (16.1 km) stream

Stream

A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...

 located in central New Hampshire

New Hampshire

New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It is a tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Suncook River

Suncook River

The Suncook River is a river located in central New Hampshire in the United States. It is a tributary of the Merrimack River, which flows to the Gulf of Maine....

, part of the Merrimack River

Merrimack River

The Merrimack River is a 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 Atlantic Ocean at Newburyport...

 (and therefore Gulf of Maine

Gulf of Maine

The Gulf of Maine is a large gulf of the Atlantic Ocean on the east coast of North America.It is delineated by Cape Cod at the eastern tip of Massachusetts in the southwest and Cape Sable at the southern tip of Nova Scotia in the northeast. It includes the entire coastlines of the U.S...

) watershed

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

. Its entire course is within Bear Brook State Park

Bear Brook State Park

Bear Brook State Park is a preserve located in Allenstown, New Hampshire and surrounding towns. It is one of New Hampshire's largest state parks....

.

Bear Brook begins at the outlet of Hall Mountain Marsh near the four-corner intersection of the towns of Allenstown

Allenstown, New Hampshire

Allenstown is a town in Merrimack County, New Hampshire, United States. The population was 4,322 at the 2010 census. Allenstown includes a portion of the village of Suncook. Just over one-half of the town's area is covered by Bear Brook State Park....

, Deerfield

Deerfield, New Hampshire

Deerfield is a town in Rockingham County, New Hampshire, United States. The population was 4,280 at the 2010 census. Deerfield is home to the annual Deerfield Fair.- History :...

, Candia

Candia, New Hampshire

Candia is a town in Rockingham County, New Hampshire, United States. The population was 3,909 at the 2010 census. The town includes the villages of Candia, Candia Four Corners and East Candia.-History:...

, and Hooksett

Hooksett, New Hampshire

Hooksett is a town in Merrimack County, New Hampshire, United States. The population was 13,451 at the 2010 census. The town is located between Manchester, the state's largest city, and Concord, the state capital...

. The brook descends to the north, through Deerfield, then turns west and reenters Allenstown. Nearing Deerfield Road, the brook is impounded by Catamount Pond, with a state park beach and picnic area. The brook flows northwest from the pond and reaches the Suncook River in less than a mile.