The Annisquam River is a tidal, salt-water estuary

Estuary

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea....

 in Annisquam

Annisquam, Massachusetts

Annisquam is a small waterfront neighborhood located in the City of Gloucester located on the North Shore of Massachusetts.-History:The name "Annisquam" comes from an Algonquian term meaning "top of the rock, containing , "on top of", and , "rock". The first European settlement in Annisquam was...

 and Gloucester, Massachusetts

Gloucester, Massachusetts

Gloucester is a city on Cape Ann in Essex County, Massachusetts, in the United States. It is part of Massachusetts' North Shore. The population was 28,789 at the 2010 U.S. Census...

, connecting Annisquam Harbor on the north to Gloucester Harbor on the south. The segment between Gloucester Harbor and the Boston

Boston

Boston is the capital of and largest city in Massachusetts, and is one of the oldest cities in the United States. The largest city in New England, Boston is regarded as the unofficial "Capital of New England" for its economic and cultural impact on the entire New England region. The city proper had...

 and Maine

Maine

Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

 railroad bridge is also known as the Blynman Canal.

The estuary is about 4.5 miles (7.2 km) long, navigable, and open to the ocean at both ends. Its surface area is 1.9 square miles (4.9 km²). The name "Annisquam" comes from an Algonquian

Algonquian languages

The Algonquian languages also Algonkian) are a subfamily of Native American languages which includes most of the languages in the Algic language family. The name of the Algonquian language family is distinguished from the orthographically similar Algonquin dialect of the Ojibwe language, which is a...

 term meaning "top of the rock, containing , "on top of", and <-ompsk>, "rock". The first European settlement in Annisquam was established in 1631. The river was dredged by the United States Army Corps of Engineers

United States Army Corps of Engineers

The United States Army Corps of Engineers is a federal agency and a major Army command made up of some 38,000 civilian and military personnel, making it the world's largest public engineering, design and construction management agency...

 in 1965 to create a channel some 8 feet (2.4 m) deep, and 60 to 200 feet (61 m) wide. Annisquam Harbor Light

Annisquam Harbor Light

Annisquam Harbor Light Station is a historic lighthouse on Wigwam Point in the Annisquam neighborhood of Gloucester, Massachusetts.- History :...

stands on the east, Cape Ann, side of the north entrance to the river.