Potomac River

The Potomac River is a large river in the Mid-Atlantic region of the United States. It flows from the Potomac Highlands in West Virginia to the Chesapeake Bay in Maryland. The river is 405 miles long and has a drainage area of 14,700 square miles, making it the fourth-largest river along the East Coast of the United States. Many people live near the river.

The Potomac River forms a boundary between different areas. On one side are Maryland and Washington, D.C., and on the other side are West Virginia and Virginia. Special parts of the river were named a National Recreation Trail in 2006, and a part in Charles County, Maryland, became the Mallows Bay–Potomac River National Marine Sanctuary in 2019.

The river is very important in history and politics. The nation’s capital, Washington, D.C., is located on its banks, as is Mount Vernon, the home of George Washington. During the American Civil War, the river separated two sides, and a large army was named after it.

Course

The Potomac River is 405 miles long. It starts at the Fairfax Stone Historical Monument State Park in West Virginia and ends at Point Lookout in Maryland. The river has two main parts, called the North Branch and the South Branch. These two branches meet near Shepherdstown, West Virginia to form the Potomac River.

The North Branch starts at the Fairfax Stone. It flows through several towns before meeting the South Branch. The South Branch begins near Hightown in Virginia. It flows through different areas and joins the North Branch to make the Potomac River. The river goes through five natural areas on its way to the Chesapeake Bay. Below Little Falls, tides affect the river as it passes through Washington, D.C. The water becomes saltier as it gets closer to the Bay.

Main article: North Branch Potomac River

Main article: South Branch Potomac River

From where the North and South Branches meet, the river runs through Opequon Creek. Several smaller streams flow into the river along this part.

From just above Harpers Ferry in West Virginia to Little Falls in Maryland, many small streams and creeks join the river here.

The Tidal Potomac River is the part of the river below the Fall Line. It is 108 miles long and runs from just below Washington, D.C., to the Chesapeake Bay. Many smaller rivers flow into the Potomac along this part.

History

Natural history

The Potomac River is very old, at least 3.5 million years. It may be even older. The river has changed shape, especially around Great Falls, when glaciers covered the land.

Human history

The Potomac River has been home to Native American people for a very long time. Many groups lived along the river, such as the Piscataway and their allies.

In 1608, explorer Captain John Smith traveled up the river and made maps. He called it "Patawomeck" based on what local people told him. Over time, the name changed to "Potomac".

The river was important during the American Civil War. It separated the two sides and was crossed by soldiers many times. Important battles happened nearby.

George Washington spent much of his life near the river. The nation’s capital, Washington, D.C., is also close to the Potomac. The river has been used for transportation and as a water source for the city.

Hydrology

Water supply and water quality

In the Washington area, the Potomac River provides a lot of water every day. This water helps millions of people living there.

In the past, the Potomac River wasn't very clean because of pollution from mining, farming, and cities. Leaders worked to clean the river, and laws were made to stop pollution. Today, the river is much cleaner, and people can enjoy activities like fishing and boating. The river still needs care to stay clean.

Discharge

The Potomac River usually flows at a steady rate. In March 1936, it flowed much faster than usual, and in September 1966, it flowed much slower than usual.

Legal issues

Maryland and Virginia have disagreed about who controls the Potomac River. Long ago, they made agreements giving both states rights to the river. In 1776, Virginia agreed to share the river but kept some rights. They made more agreements in 1785 and 1877. These decided that Maryland would control the river from bank to bank, but Virginia could still use it.

In 1996, Maryland refused a request from Virginia to build a water system near the river. Virginia took the issue to the Supreme Court of the United States, which decided in favor of Virginia in 2003.

When West Virginia became a state in 1863, there were questions about its rights to land and the river. The Supreme Court settled these in 1910.

Fauna

Fish

The Potomac River has many kinds of fish, such as bass, muskellunge, pike, and walleye. An invasive fish called the northern snakehead was first seen here in 2004. You can also find sunfish in the river. Although it’s rare, bull sharks sometimes visit too.

The number of American shad in the river has grown again thanks to a project that started in 1995. This project added young shad to the river and built a special path to help adult shad get past a dam.

Mammals

When Europeans first lived near the Potomac, large animals such as bison, elk, wolves (gray and red), and cougars were there, but they were hunted until they disappeared. Beavers and otters also disappeared, but small groups of American mink and martens survived.

People reported seeing Atlantic bottle-nosed dolphins in the 1800s. In July 1844, a group of dolphins was seen near the Aqueduct Bridge.

Since 2015, many more of these dolphins have been seen in the Potomac. Scientists believe this is because of warmer weather and cleaner water in the river.

Birds

Reptiles

Amphibians