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New Hampshire Department of Environmental Services

Designated Rivers
The Isinglass River Report to the General Court

isinglass riverBeginning at the outlet of Bow Lake, the Isinglass River flows freely for approxproximately 18 miles through the communities of Strafford, Barrington, and Rochester until it joins the Cocheco River. The Isinglass River watershed, which includes the Mohawk River, Nippo Brook, Berrys River, Green Hill Brook, and the outlets of Hanson and Ayers Ponds, is approximately 75 square miles. Despite being situated in one of the fastest growing regions of the state, the Isinglass River is appreciated from a state and local perspective for itsas having outstanding, natural beauty, historical, educational, educational, water supply and quality, recreational, and wildlife and plant characteristics.

Natural Beauty

Most of the Isinglass remains in a naturral state with its banks lined by natural vegetation. There are few docks and, no manmade impoundments or diversions (not including withdrawals) along its entire length. Numerous areas of rapids occur along the river, including Locke's Falls, which is a site of singular beauty.

The beauty of the Isinglass in its present natural state is threatened by its location in one of the two most rapidly growing areas of the state. It does not have the protection afforded streams in more remote areas. The Regional Watershed map appended shows the river's proximity to the Seacoast.


isinglass river

The Isinglass offers pre-European archaeological evidence of Native American trails and living sites in its corridor. A Squamnanamagonic American Indian settlement in present-day Gonic is currently being restored.

The Isinglass also offers archeological sites that define the evolution of local economies from the eighteenth 18th century through to the mid-twentieth 20th century. A series of mills once operated along the river and its tributaries, which are now evidenced by their remaining foundations. The mills bear witness to production activities ranging from lumbering to agricultural products to fabric. Currently underway are efforts recognizing these mills collectively as a Historic District of value in New Hampshire's economic history. The Ayers Lake Campground, on Ayers Pond, which drains into the Isinglass via Betty's Brook, has been declared eligible at the state level for recognition as a Historic Site of early tourism. The ancestors of the present owners built its cabins in the last quarter of the 19th century.


The Isinglass has served as a laboratory for local students in grades K-12. The use of a river that is local, and known to the students, has promoted a strong sense of stewardship and provided a unique incentive and opportunity to engage them in projects such as water testing, examining drainage patterns, wildlife and plant identification, and investigating land use over time. In collaboration with the Cocheco River Watershed Coalition, the Isinglass communities are taking advantage of on-going opportunities to develop appropriate river-related curricula and provide teacher training.

Water Supply and Quality

The Isinglass contributes directly to the drinking water of the City of Dover and recharges numerous wells along its length. The River recharges Barrington's northern aquifer. Its high quality contributes significantly to the health of the water body into which it flows; the Cocheco River.


Present-day Bow Lake is approximately twice as large as it was before a dam was erected at the origin of the Isinglass. The expanded lake provides excellent swimming, boating, and fishing opportunities that are available to residents and visitors. Below the dam, the river is actively used for hiking, fishing, swimming, and boating. The Isinglass is referred to in the AMC River Guide/New Hampshire-Vermont as having 10 miles of flatwater and quickwater of Class I and II, navigable during high water from late March to the end of April. The Isinglass has formal and informal public access sites including canoe access at three sites. More access information can be found on The Isinglass River Nomination web page.

Wildlife Habitat and Uncommon Vegetation

The Isinglass River provides habitat for many species of wildlife, such as deer, beaver, mink, and barred owls. Significant areas of unfragmented land still exist and offer river-access to wildlife. In a number of sections, the river connects unfragmented parcels. Rare natural communities such as a Black Gum/Red Maple Basin Swamp and a Northern New England Rich Mesic Forest are found within these parcels. Uncommon herbaceous species, such as wild lupine and yellow lady slipper, have also been identified within the river corridor.

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