Souhegan River is a River located in Hillsborough County, NH. Starting in New Ipswich, NH the Souhegan River flows 34 miles through Milford, NH before ending in Merrimack, NH. The Souhegan River rises to an elevation of 98 feet and has a surface area of 8,572,038 square miles. Find maps, fishing guides, weather and recreation information at Guidesly.

About Souhegan River, NH

The Souhegan River in southern New Hampshire is one of the largest tributaries to the Merrimack River, with a drainage area of approximately 425 square miles. It runs around 34 miles via the communities of New Ipswich, Greenville, Wilton, Milford, Amherst, and Merrimack before fusing with the Merrimack River. The river starts in New Ipswich, at the junction of its South and West Branches. Upstream, the river passes over Wildcat Falls then crosses under Everett Turnpike and U.S. Route 3.

Over three centuries ago, a group of Penacook Indians settled on the banks of the river they named ‘Souhegan’ which roughly translates to ‘river of the plains’ or ‘river of difficult portages’. Other sources indicate the river’s name comes from the language of the Native American Algonquins, meaning ‘waiting and watching place’. The area became popular for European settlers in the 1700s, resulting in the development of agrarian land, the establishment of mills, and the incorporation of towns. Currently, some communities in the Souhegan River corridor maintain a strong manufacturing role, transitioning to other sectors such as electronics, defense, and computer technology.

The river, with its stratified drift aquifers, is used for water supplies, a small amount of hydropower, and recreation; including fishing. There are 28 threatened or endangered species sharing the watershed with locals. It is part of the New Hampshire Rivers Management Protection Program and was one of two rivers studied by the New Hampshire Department of Environmental Services to reach data and recommendations about allowable ‘instream flow’ which benefits fish found in the river. Fine sands and silts that underlie the floodplains of the river were left behind as a result of Lake Merrimack extending up the river to Milford Center during the last ice age. 

All About Fishing in Souhegan River, NH

The Souhegan River is a great spot to fish in New Hampshire as the state’s Fish and Game Department stocks it heavily annually. Native fish that can be found in the river include a variety of trout (rainbow, brown, brook, and steelhead), bass (largemouth and smallmouth), sunfish, perch (white and yellow), suckers, and dace. The upper reaches of the river and its tributaries provide an ideal home for the Atlantic salmon, Carp, graylings, tarpons, bonefish, permit, and taimen can also be found in the river. The river was also a notable part of the discontinued Merrimack River Anadromous Fish and was considered one of the most productive rivers in the watershed.

The Milford area is where most prefer to fish as the river is filled with long stretches of pocket water, technical glides, and deep pools. As a result, there are plenty of fishing spots to choose from. Experienced anglers have recommended fishing at North River Road Bridge, Monadnock Water, under the Route 31 bridge, and north of the closed John Storrs Bridge. Whether you’re fly fishing, spinning, and baitcasting, chances of getting a bite are good since the Souhegan River is mostly put-and-take, with fish not being too picky. Wading is also recommended for calmer and shallow spots in the river. Boating is limited to canoes and kayaks due to generally low water depth. The river has been identified as good, intermediate whitewater, with rapids in the Greenville and Wilton, stretch classified as Class II, III, and IV whitewater. Public access sites are available in the towns of Merrimack, Amherst, Milford, and Wilton.

In 2018 and 2020, the Environmental Protection Agency, as well as the New Hampshire Department of Environmental Services, issued a warning about eating fish caught between the Riverway East and Goldman Dam as well as a part near Milford due to freshwater sources containing polychlorinated biphenyls (PCBs) or dioxin. The chemicals have been linked to cancer and other human health issues. It’s recommended that you check if you are part of a high-risk or low-risk group from eating fish caught in the river. How much fish from the river is safe to consume at a period of time should also be looked up. 

Fishing Seasonality

The Souhegan River is mostly abundant in trout all-year round. Fish and Game stock the river heavily during the spring when wild brook trout is apparently present. Bass can be caught during the same period as trout with a catch-and-release season from May to June. Salmon can be caught from April to September. According to New Hampshire Freshwater Fishing, October 16 to June 15 is the catch-and-release period with single barbless hook artificial lures and flies permitted. There is also a daily limit of 5 brook trout or 5lbs of the fish from June 16 to October 15. The rest of the fish species are mostly available from January to October with rivers in the state generally closed from October through December.

Fishing Seasonality

The Souhegan River is mostly abundant in trout all-year round. Fish and Game stock the river heavily during the spring when wild brook trout is apparently present. Bass can be caught during the same period as trout with a catch-and-release season from May to June. Salmon can be caught from April to September. According to New Hampshire Freshwater Fishing, October 16 to June 15 is the catch-and-release period with single barbless hook artificial lures and flies permitted. There is also a daily limit of 5 brook trout or 5lbs of the fish from June 16 to October 15. The rest of the fish species are mostly available from January to October with rivers in the state generally closed from October through December.

All About Fishing in Souhegan River, NH

The Souhegan River is a great spot to fish in New Hampshire as the state’s Fish and Game Department stocks it heavily annually. Native fish that can be found in the river include a variety of trout (rainbow, brown, brook, and steelhead), bass (largemouth and smallmouth), sunfish, perch (white and yellow), suckers, and dace. The upper reaches of the river and its tributaries provide an ideal home for the Atlantic salmon, Carp, graylings, tarpons, bonefish, permit, and taimen can also be found in the river. The river was also a notable part of the discontinued Merrimack River Anadromous Fish and was considered one of the most productive rivers in the watershed.

The Milford area is where most prefer to fish as the river is filled with long stretches of pocket water, technical glides, and deep pools. As a result, there are plenty of fishing spots to choose from. Experienced anglers have recommended fishing at North River Road Bridge, Monadnock Water, under the Route 31 bridge, and north of the closed John Storrs Bridge. Whether you’re fly fishing, spinning, and baitcasting, chances of getting a bite are good since the Souhegan River is mostly put-and-take, with fish not being too picky. Wading is also recommended for calmer and shallow spots in the river. Boating is limited to canoes and kayaks due to generally low water depth. The river has been identified as good, intermediate whitewater, with rapids in the Greenville and Wilton, stretch classified as Class II, III, and IV whitewater. Public access sites are available in the towns of Merrimack, Amherst, Milford, and Wilton.

In 2018 and 2020, the Environmental Protection Agency, as well as the New Hampshire Department of Environmental Services, issued a warning about eating fish caught between the Riverway East and Goldman Dam as well as a part near Milford due to freshwater sources containing polychlorinated biphenyls (PCBs) or dioxin. The chemicals have been linked to cancer and other human health issues. It’s recommended that you check if you are part of a high-risk or low-risk group from eating fish caught in the river. How much fish from the river is safe to consume at a period of time should also be looked up.