The Harlem River is a tidal waterway in New York City. It is about 8 miles (13km) long and separates the island of Manhattan from the Bronx. It connects the Hudson River on the north and west with the East River on the south and east.
Even though it is called a river, the Harlem River is really a strait. Its water moves in both directions because of the ocean tides.
The northern part of the waterway includes the Harlem River Ship Canal and Spuyten Duyvil Creek. The canal was built in the late 1800s to make travel by boat easier. The work changed the shape of northern Manhattan and separated Marble Hill from Manhattan Island.
The Harlem River begins where the Hudson River meets Spuyten Duyvil Creek at the northern end of Manhattan. It runs southeast between Manhattan and the Bronx before joining the East River near Randalls and Wards Islands.
The waterway is part of the larger New York–New Jersey Harbor Estuary. Its shore has been changed greatly by roads, railroads, bridges, buildings, and seawalls.
The current can be strong because the river is tidal. Water can move northwest toward the Hudson River or southeast toward the East River, depending on the tide.
The channel is used mainly by small commercial boats and recreational boats. Large ships use it less often because many bridges cross the river.
History
Before major development
Before New York City became heavily built up, the Harlem River area had tidal marshes, small streams, rocky shorelines, and wetlands.
About 25 streams once flowed into the Harlem River watershed. Most were later filled in or placed in underground pipes as the city grew. One of the largest was Tibbetts Brook in the Bronx.
The Lenape lived around Manhattan and the Bronx before Europeans settled the area. The Harlem River and its nearby wetlands provided fish, shellfish, plants, and routes for travel.
Early bridges
People have crossed the northern Harlem River for hundreds of years. The first King's Bridge was built in 1693 near the northern end of Manhattan. Travelers had to pay a toll unless they were working for the British government.
A second bridge called the Free Bridge opened nearby in 1758. Unlike King's Bridge, travelers did not have to pay a toll. British troops destroyed it during the American Revolutionary War, but it was rebuilt after the war.
More bridges were built as Manhattan and the Bronx grew during the 1800s and early 1900s.
High Bridge
The High Bridge
The High Bridge opened in 1848. It was built to carry the Croton Aqueduct over the Harlem River and bring clean drinking water into Manhattan.
It is the oldest standing bridge in New York City. It was designed to look like an ancient Roman aqueduct.
Several original stone arches were removed during the 1920s and replaced by a large steel arch. This gave boats more room to pass underneath.
The bridge later stopped carrying drinking water and was closed to the public for more than 40 years. After a major restoration, it reopened to walkers and bicyclists on June 9, 2015.
Harlem River Ship Canal
The natural northern end of the Harlem River once curved around Marble Hill through Spuyten Duyvil Creek. The winding creek was difficult for larger boats to use.
The federal government and New York City supported a plan to build a straighter shipping canal. The Harlem River Ship Canal opened in 1895.
The canal cut through the narrow neck of land that connected Marble Hill to Manhattan Island. This made Marble Hill an island for a short time. The old part of Spuyten Duyvil Creek was later filled in, mainly by 1914, connecting Marble Hill to the Bronx mainland.
Because the city boundary did not change, Marble Hill is still legally part of the borough of Manhattan even though it is now physically attached to the Bronx.
Rowing
The large Columbia University "C" beside the river
The Harlem River became one of New York City's main places for rowing during the late 1800s and early 1900s.
More than ten rowing clubs and boathouses once stood along the river. In 1902, more than 1,000 rowers were active there.
Columbia University has a long history of rowing on the Harlem River. A large white letter "C" has been painted on a rock beside the river since 1952.
Rowing still takes place on the river. Harlem River Community Rowing was founded in 2006 and runs rowing programs from a dock at Muscota Marsh in northern Manhattan.
Harlem River Speedway
During the 1890s, New York City built a special road along the Manhattan side of the river for horses and carriages.
The Harlem River Speedway ran from about West 155th Street to Dyckman Street. Construction began in 1894, and it opened in July 1898.
At first, it was mainly for wealthy people who wanted to race or exercise horses. Bicycles were not allowed. Large crowds also came to watch horse and boat races.
Cars were later allowed on the road. The old speedway was eventually rebuilt as part of the Harlem River Drive.
Fort George Amusement Park
The west side of the river was also a place for entertainment.
Fort George Amusement Park opened in 1895 near what is now the northern end of Highbridge Park. It had roller coasters, Ferris wheels, music halls, saloons, a skating rink, and other attractions.
The park was sometimes called "Harlem's Coney Island". It was badly damaged by fires in 1911 and 1913. It closed after the 1913 fire, and its land later became part of Highbridge Park.
Transportation
The Harlem River is crossed by road bridges, railroad bridges, pedestrian bridges, subway tunnels, and railroad tunnels.
Many of the road bridges are movable. They can swing or lift out of the way so taller boats can pass.
The Willis Avenue, Third Avenue, Madison Avenue, 145th Street, Macombs Dam, and University Heights bridges use swing spans. A swing bridge turns sideways to open a channel for boats.
The Broadway and Wards Island bridges use lift spans. The center section of a lift bridge moves upward.
The Spuyten Duyvil railroad bridge also moves to let boats pass.
Macombs Dam Bridge
The present Macombs Dam Bridge opened in 1895. It is one of New York City's oldest major bridges and the oldest surviving swing bridge in the city that still has its original basic form.
An earlier dam and bridge had been built there in 1814. The dam blocked boat traffic and caused flooding. In 1839, local people broke through the dam with a coal boat. A court later ruled that blocking the river had been a public nuisance.
Broadway Bridge
The Broadway Bridge carries both road traffic and the New York City Subway.
An earlier swing bridge opened there in 1895. That bridge was later moved to West 207th Street, where part of it became the University Heights Bridge.
The present Broadway Bridge uses a vertical-lift span.
Parks and waterfront
Several parks are beside the Harlem River. These include Highbridge Park, Roberto Clemente State Park, Sherman Creek Park, and parks near Randalls Island.
For many years, the Bronx side of the Harlem River had fewer continuous public paths because railroad lines, highways, industrial land, and other properties blocked access to the shore.
Harlem River Greenway
New York City is building a longer Harlem River Greenway in the Bronx.
Planning began in 2023. By 2026, several sections had already been built or improved, including parts of Bailey Avenue, Depot Place, and Bruckner Boulevard.
The project is meant to make it easier for people in Bronx neighborhoods to walk or bicycle along the river and reach parks and bridges.
Environment
The Harlem River has been changed greatly since the 1800s.
Natural streams were buried, wetlands were filled, and much of the shoreline was covered with walls or stone. Railroads, roads, industry, and buildings were built close to the water.
For many years, sewage pollution was a serious problem. New York City's sewer system still sends some combined sewage and rainwater into the river during heavy storms.
Water quality has improved because of sewage-treatment projects and other environmental work. In 2025, New York State changed the water-quality goals for the Harlem River as part of a plan to make more New York City waterways suitable for swimming and fishing in the future.
This does not mean that the Harlem River is always safe for swimming. New York State says people should swim only at officially approved beaches.
The study is looking at ways to restore wildlife habitat, improve water quality, reduce flooding, and give the public better access to the waterfront.
Tibbetts Brook project
Tibbetts Brook once flowed naturally through the Bronx into the Harlem River. Much of it was later buried in the sewer system.
New York City is working to bring part of the brook back above ground. This is called daylighting a stream.
In June 2026, the city announced that a $149.5 million construction contract had been awarded. Construction was expected to begin in fall 2026.
The project will send more clean brook water directly toward the Harlem River instead of into the sewer system. The city says this should reduce sewer overflows, improve water quality, and create new green space.
Recreation
The Harlem River is used for rowing, kayaking, bicycling, walking, and fishing.
The river has a long rowing history. Columbia University crews use it for training, and community rowing groups also operate there.
The High Bridge is now a popular walking and bicycle crossing with views of the river.
Parks and greenways along both sides of the river continue to be expanded.
