Herring Runs

Iron Hill Park

Iron Hill St, Weymouth, MA 02189, USA

Owned By: Town of Weymouth

This small town park at the edge of Whitman’s Pond features a very long, 2-part fish ladder and a viewing platform for the South Shore’s only waterfall, Iron Hill Falls (also known as Whitman’s Falls). In the spring, you can see herring making the arduous climb up Herring Run Brook to their spawning grounds in Whitman’s Pond. Please be mindful of private property! This park is currently (2021) being reviewed by the Town of Weymouth for renovations.

If you’re interested in the herring run, be sure to stop at Herring Run Pool Park, in nearby Jackson Square, where there are informational kiosks and additional views of the herring run. Herring are most commonly seen in April and May. Another spot nearby where you can view them is Stephen Rennie Herring Run Park, also in Jackson Square, contiguous with Lovell Field.


The dam on Herring Run Brook (also known as the Mill River) at the uppermost border of this park was put in place in order to provide power for the Weymouth Iron Works, a company that processed natural bog iron from Whitman’s Pond into nails, chains, anchors and shovels. Also known as the Weymouth Iron Company, it was founded in 1837, and involved a furnace, a rolling mill, and a machine shop. According to an article in the Weymouth News, “The iron works prospered through the decades before, during and after the Civil War, employing as many as 275 men. A 1923 Weymouth Historical Society volume said it was, by the early 1870s, ‘the biggest industry in town.’ But within a decade, it had competition from new, bigger iron works in Pennsylvania. A devastating flood in 1886 damaged the furnace and other equipment, and the company stopped its manufacturing a few months later.” The stone-faced building at #14 Iron Hill Road once served as the office for the Iron Works. It is now privately owned.

This land is within the region of the Massachuseuk (or Massachusett) Native American tribe.

Trail Description

No trails, but be sure to climb the hill to the observation platform, where you can view Iron Hill Falls. You can peek through the chain-link fence to view the fish ladder here. You can also view them beside the historic Iron Works building at 14 Iron Hill Street, where the fish ladder continues. Please respect private property!

Habitats and Wildlife

Iron Hill Falls, also known as Whitman’s Falls, is the only waterfall on the South Shore. It involves a 10-12 foot drop, as Herring Run Brook pours out of Whitman’s Pond and down a steep cliff. Next to the waterfall is the Iron Hill Fish Ladder, a 2-part, double-switchback fish ladder installed to help migratory fish such as herring ascend to their spawning grounds in Whitman’s Pond and beyond.

Herring Run Brook is also known as the Mill River. It flows from Whitman’s Pond into the Weymouth Back River, which flows for about 10 miles and empties into the Atlantic Ocean at Hingham Bay,  just south of Grape Island and Slate Island.

The Commonwealth of Massachusetts installed the 2-part herring ladder at this site, to help migrating herring and rainbow smelt to bypass the dam on their annual return to their spawning grounds. Herring historically spawned not only in Whitman’s Pond, but farther upstream on the Mill River and Swamp River, and in Great Pond. The annual herring run typically involves about 500,000 fish!

The term “river herring” refers to both the alewife and blueback varieties. They are born in fresh water, but spend the majority of their lives in the ocean. However they return to freshwater to spawn, usually to the same place where they were born. This happens in the spring, when the water temperature rises to about 57 degrees (late April through June).

Herring were historically caught just downstream of here, in today’s Jackson Square, where Herring Run Pool Park is now located. This is evidenced by Weymouth town records dating back to 1648. Of course, it’s likely that the aboriginal inhabitants of this region harvested herring for a long time prior to that. Through the mid-1900s, local residents considered the herring run a valuable food resource. The state constructed a fish ladder in Jackson Square in 1940, to assist river herring in their annual migration to their spawning grounds upstream.

Herring populations in the Weymouth Back River dropped significantly in the 2000s. Millions of herring were caught there annually in the 1800s, but by 2005, that number had dropped to 80,000. Improving water quality and stream access will help to restore local herring runs. While herring may no longer be an important part of the human diet, numerous local species rely on it as a food source. These include bald eagles, osprey, egrets, harbor seals, kingfishers, river otter, and a variety of marine and freshwater fish.

Iron Hill St, Weymouth, MA 02189, USA

Historic Site: No

Park: Yes

Beach: No

Boat Launch: No

Lifeguards: No

Hours: Dawn to Dusk

Parking: Limited on-site parking on Iron Hill Street.

Cost: Free

Trail Difficulty: Easy, Medium


Herring run/fish ladders, viewing platform overlooking the waterfall. Geocache location.

Dogs: Dogs must remain on leash at all times. Scoop the poop!

Boat Ramp: No

ADA Access: No

Scenic Views: Yes

Waterbody/Watershed: Herring Run Brook (Weymouth Back River watershed)

Other Things to Do at This Site