The Gunpowder River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data
The National Map
, accessed April 1, 2011 tidal inlet on the western side of the

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula, including parts of the Ea ...

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. It is formed by the joining of two freshwater rivers, Gunpowder Falls (often referred to locally as "Big Gunpowder Falls") and Little Gunpowder Falls.

Gunpowder Falls

The Big Gunpowder, long, begins in the extreme southern part of

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

's York County. From there, the Gunpowder flows in a generally southeast direction through the length of

Baltimore County Baltimore County ( , locally: or ) is the third-most populous county in the U.S. state of Maryland. The county is part of the Central Maryland region of the state. Baltimore County partly surrounds but does not include the independent city ...

past the

Perry Hall Mansion The Perry Hall Mansion is a historic structure located in the area to which it gave its name, Perry Hall, Baltimore County, Maryland, United States. Erected on a hill above the Gunpowder River Valley, the mansion is an excellent example of la ...

and the site of its former plantation until it reaches Joppatowne where it is joined by the Little Gunpowder and the Bird River, becoming simply the "Gunpowder River" once it passes the

Amtrak The National Railroad Passenger Corporation, Trade name, doing business as Amtrak (; ), is the national Passenger train, passenger railroad company of the United States. It operates intercity rail service in 46 of the 48 contiguous United Stat ...

train bridge that joins

Chase Chase or CHASE may refer to: Businesses * Chase Bank, a national American financial institution * Chase UK, a British retail bank * Chase Aircraft (1943–1954), a defunct American aircraft manufacturer * Chase Coaches, a defunct bus operator in ...

and Joppatowne. The nearby site of old Joppa was an important deep-water seaport, and rival to the port of Baltimore, in colonial American times, until

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to th ...

of the Gunpowder River -- caused by upstream development -- made its harbor inaccessible to large ships.

Little Gunpowder Falls

Little Gunpowder Falls, as its name implies, is much smaller than the mainstem Gunpowder Falls. Throughout its length, it forms much of the boundary between eastern Baltimore County and western

Harford County Harford County is a county located in the U.S. state of Maryland. As of the 2020 census, the population was 260,924. Its county seat is Bel Air. Harford County is included in the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Stati ...

until it reaches the Big Gunpowder. The headquarters of the

Gunpowder Falls State Park Gunpowder Falls State Park is a public recreation area comprising six non-contiguous areas covering in northeastern Baltimore County and western Harford County, Maryland. The state park is primarily made up of the stream valleys of the Big an ...

is located in

along the bank of the Little Gunpowder Falls, in the historic

Jerusalem Mill Village Jerusalem Mill Village is a living history museum that spans the 18th through early 20th centuries. One of the oldest and most intact mill villages in the U.S. state of Maryland, Jerusalem is located in Harford County, along the Little Gunpow ...

. The remainder of the boundary between Baltimore and Harford counties is formed by the Gunpowder River, the tidal

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime enviro ...

of the

formed by the union of Little Gunpowder Falls and the Gunpowder Falls rivers.

Recreation

Both the Gunpowder and Little Gunpowder Falls flow through hilly agricultural and forest land for much of their length. In fact, there are no less than four separate

state park State parks are parks or other protected areas managed at the sub-national level within those nations which use "Federated state, state" as a political subdivision. State parks are typically established by a state to preserve a location on accou ...

s that form

, the largest state park in Maryland. At two points, Gunpowder Falls is dammed to form major

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

s for the

Baltimore metropolitan area The Baltimore–Columbia–Towson Metropolitan Statistical Area, also known as Central Maryland, is a metropolitan statistical area (MSA) in Maryland as defined by the United States Office of Management and Budget (OMB). It is part of the larger ...

Prettyboy Reservoir Prettyboy Reservoir is a reservoir in the Hereford Zone of northern Baltimore County, Maryland. While the reservoir is in Baltimore County, the independent city of Baltimore owns the reservoir and the surrounding land. The reservoir is one of ...

and

Loch Raven Reservoir The Loch Raven Reservoir is a reservoir that provides drinking water for the City of Baltimore and most of Baltimore County, Maryland, Baltimore County, Maryland. It is fed by the Gunpowder River, Big Gunpowder Falls river, and has a capacity of ...

. By the time the Gunpowder reaches the Bay, however, it is no longer a rural river, but a suburban river that passes under

Interstate 95 Interstate 95 (I-95) is the main north–south Interstate Highway on the East Coast of the United States, running from U.S. Route 1 (US 1) in Miami, Florida, north to the Houlton–Woodstock Border Crossing between Maine and the ...

and many

bedroom communities A commuter town is a populated area that is primarily residential rather than commercial or industrial. Routine travel from home to work and back is called commuting, which is where the term comes from. A commuter town may be called by many o ...

for Baltimore. Nonetheless, Gunpowder State Park on the Chesapeake Bay may give one the impression that this is still a somewhat remote river. Both streams flow over the

Fall Line A fall line (or fall zone) is the area where an upland region and a coastal plain meet and is noticeable especially the place rivers cross it, with resulting rapids or waterfalls. The uplands are relatively hard crystalline basement rock, and the ...

separating the

Piedmont Plateau The Piedmont ( ) is a plateau region located in the Eastern United States. It is situated between the Atlantic Plain and the Blue Ridge Mountains, stretching from New York in the north to central Alabama in the south. The Piedmont Province i ...

from the

Atlantic Coastal Plain The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

just downstream of

US Route 1 U.S. Route 1 or U.S. Highway 1 (US 1) is a major north–south United States Numbered Highway that serves the East Coast of the United States. It runs from Key West, Florida, north to Fort Kent, Maine, at the Canadian border, ma ...

. This creates some class III

whitewater Whitewater forms in the context of rapids, in particular, when a river's Stream gradient, gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that foam, froths, making t ...

opportunities for kayakers and canoeists when the water is reasonably high. The section of the Gunpowder River between Pretty Boy Reservoir and Loch Raven Reservoir is a popular fly fishing destination. The section of river is home to wild brown trout and rainbow trout. There is also a small population of brook trout

Tributaries

*Minebank Run *Long Green Creek *Sweathouse Run *Haystack Branch *Jennifer Branch *Bean Run *Foster Branch *Taylor Creek *Broad Run

References

External links