At its mouth, the Assonet River also forms Hathaway Cove in Assonet. From this general location, it flows northeast between Assonet and Berkley, eventually forming Shepherd's Cove in Assonet on its eastern side. From here, the river turns more northward and forms the beautiful Assonet Bay, a large inland body of water. Assonet Bay branches in several directions:
From this point, the river runs under Route 24 and into Assonet Village, where it becomes much narrower and runs through the center of the Village. This portion of the river essentially stops west of Mill Street in Assonet, where a dam has created a waterfall. On top of the dam, the river continues to parallel Mill Street until Forge Road, where another dam divides the river. This dam forms Forge Pond. On the northwest of Forge Pond is Quaker Brook. To the northeast, the Assonet River continues until the tri-border of Assonet, Berkley, and Lakeville. At this point, it becomes Cedar Swamp River.
The Assonet River is a major river of southeastern Massachusetts, along with the Taunton River. Throughout the history of colonial and early America, the river provided the necessary power for gristmills and sawmills, and later the Crystal Springs Bleachery. It provided for a minor port, and is also a prime location for herring runs.
During the 18th century, the river played a part in the American Revolutionary War. British ships travelled both it and the Taunton River when fighting in the colonies. Such attacks led to the Battle of Freetown, as well as the burning of river-centered village centers.
During the 19th century, fishing and cargo ships regularly used the Assonet River to reach their home port of Assonet, Massachusetts. From these ports on Water Street and South Main Street were delivered products such as food, dairy, lobster, fish, lumber, and for a span of time guns. The N. R. Davis Gun Factory, located on Water Street adjacent to the river, supplied many weapons to forces in the Civil War.
In the 20th century, the river continued to see its share of action, but only briefly. The last ship to sail from Assonet set out in 1902. Small bootlegging operations used the river sporadically. The Green Dragon Tavern was torn down in the 1930s, and the Town of Freetown constructed its bandstand on the riverside site, providing a wonderful greenspace. The gun factory burned in 1925, and the bleachery followed suit in 1955, essentially bringing the commercial life of the river to a close.
Assonet Bay Shores, a former summer community, is a peninsula formed by Assonet Bay, Payne Cove, and Shepherd's Cove. It was first settled early in Assonet's history, with this major development following in the early 1960s. Across Shepherd's Cove is an abundance of higher-end homes, proving that the river has found new life as a beautiful backdrop for rural life.