The Largest Dam in Each of the 50 States

Written by Justin Sexton
Updated: October 30, 2023
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Dams are vital to the creation of lakes and water control. The river water behind the dams rises and forms artificial lakes called reservoirs. The water from the dams can serve multiple purposes as a source of power for cities and drinking water. There are four different types of dams: Embankment, Gravity, Buttress, and Arch dams.

  • Embankment- This is the most common type of dam in America. These structures are made of either rock or clay elements. They can have clay layers to stop leaks through the gaps in the rock.
  • Gravity- They are concrete dams that use their weight to hold back the water. The side of the dam that holds the water back is straight. It’s also expensive to build Gravity Dams due to the large usage of concrete.
  • Buttress- This type contains buttresses or a series of supports that braces the dam on the downstream side.
  • Arch- They are curved in shape. Their curved shape holds the water in the reservoir. They’re thinner than the other dam types and don’t require as many materials as the other types.

In the United States, there are over ninety-one thousand dams! The amount also includes the ones in the American territories of Guam and Puerto Rico. This article will cover the largest dams in each of the fifty states. This will not include the ones in the U.S. territories of Guam and Puerto Rico.

Hoover Dam Is The Largest Dam In Arizona and Nevada!

Hoover Dam And The Mike O'Callaghan - Pat Tillman Memorial Bridge Viewed From The Arizona Side

Hoover Dam And The Mike O’Callaghan – Pat Tillman Memorial Bridge Viewed From The Arizona Side.

©Jim Vallee/Shutterstock.com

This entry covers both Arizona and Nevada Entries. The Hoover is 726 feet tall. It is an Arch and Gravity Dam. Since its inception in 1936, this structure has helped with flood control, irrigation, and energy generation at the Colorado River on the border of Nevada and Arizona. It took 3.3 million cubic feet of concrete to build the Hoover.

Green Lake Dam In Alaska

An infographic on the Green Lake Dam

This is a relatively young structure compared to the other ones in this list. It’s 1,130 feet long and 160 feet high. The structure is located south of Sitka, Alaska and it plays a role in water conversion. Sitka, Alaska is on the western coast of Banarof Island in the Gulf of Alaska. It impounds Green Lake, which is a natural lake fed by glacial runoff.

Lewis Smith Dam In Alabama

Birmingham, Alabama

Birmingham, Alabama skyline at Railroad Park.

©SeanPavonePhoto/iStock via Getty Images

The Lewis Smith structure is three hundred feet tall. It helped in the creation of Lewis Smith Lake in 1961. Its main purpose is to help control river traffic and produce hydroelectric power at the Sipsey Fork of the Black Warrior River. Several houses and gravesites were relocated to help produce the pathway for the structure. Yet, it’s unclear historically how many houses and families were impacted by its construction. It contains two electric generators.

Bull Shoals Dam In Arkansas

A Bull Shoals infographic.

This Arkansas entry helps provide electricity to many homes and businesses across Arkansas and Missouri. Bull Shoals is a two hundred fifty-six feet behemoth. The concrete gravity dam also created the Bull Shoals Lake. Its spillways feature seventeen gate bays and its total capacity is 112,000 cubic feet per second. The Bull Shoals structure helps with controlling the White River’s water flow to prevent potential flooding.

Oroville Dam In California

A sunny day at Lake Oroville

©Quinn Comendant, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons – License

The Oroville structure is a 770-foot-tall embankment dam in Oroville, California. The Northern California structure is the tallest dam in the United States. It impounds Lake Oroville, the second-largest artificial reservoir in the United States. Oroville serves many purposes in water regulation, hydroelectric power production, and flood control. Since its inception in 1968, it controlled the flow of the Feather River to provide irrigation for the San Joaquin Valley and industrial water supply companies in Southern California.

In 2017, the main and emergency spillways appeared to be failing. It led to the evacuation of over one hundred thousand individuals. Once water levels reached below the emergency spillway levels, the emergency evacuation was lifted.

Morrow Point Dam At Colorado

US flag in front of red rock formation at Roxborough State Park in Colorado

US flag in front of red rock formation at Roxborough State Park in Colorado

©Yobab/iStock via Getty Images

The Morrow Point Dam is a concrete arch structure that’s 468 feet tall. It’s on the Gunnison River in the Upper Black Canyon. The structure creates the Morrow Point Reservoir and within the Curecanti National Recreation Area. Its primary purpose is for hydroelectric power generation.

The Colebrook River Dam In Connecticut

Campbell Falls, Connecticut

Campbell Falls State Park is a local favorite since it has roaring waterfalls that provide for a relaxing trek.

©iStock.com/Jennifer Yakey-Ault

The largest dam in Connecticut belongs to the Colebrook River Dam. It’s an embankment type of structure at Farmington River. It was fully built in 1969. It’s 1,300 feet long and 223 feet high. Since its inception, it reduced extreme flooding from the Farmington River and downstream flooding of the Connecticut River. Nowadays, the dam creates reservoirs that people visit for recreational activities.

Edgar M. Hoopes Dam In Delaware

The Largest Dam in Delaware infographic

The largest dam in Delaware belongs to the Edgar M. Hoopes Dam. It’s named after the chief engineer of the Wilmington Water Department, Edgar M. Hoopes. A nickname for the 135-foot-high structure is the Old Mill Stream Dam. It serves the Hoopes Reservoir which is Delware’s largest reservoir. This structure came to be during the Great Depression in 1932. The designers for this project added trails, monuments, and park benches for recreational purposes.

Jim Woodruff Dam In Florida

The Jim Woodruff Dam is the Largest Dam in Florida
Jim Woodruff Dam infographic.

Sneads, Florida is home to the Jim Woodruff Dam. It’s one of the smallest dams on this list at ninety-two feet. It impounds Lake Seminole to provide hydroelectric power, ensure proper water quality, and assist with river navigation. James Woodruff Sr. is a Georgia businessman who helped provide funding for the concrete gravity structure.

Carters Dam In Georiga

Infographic of Carters Dam
The dam got its name from a wealthy Georgian named Farish Carter, who lived in the area in the 1800s.

The large 445-foot-tall embankment dam is on the Coosawaatee River. Its main purpose is to provide flood control and power generation. This embankment structure created Carters Lake, which is 450 feet deep and has sixty-two miles of shoreline.

Alexander Dam In Hawaii

An infographic on the Alexander Dam

Hawaii’s largest dam belongs to the Alexander Dam. The embankment structure is 620 feet long and 125 feet high. It’s able to hold 800 million gallons of water so it can water sugar cane crops at Wahiawa Stream Mauka.

Dworshak Dam In Idaho

Dworshak Dam infographic.

This Idaho structure is at the North fork of the Clearwater River. It helps with flood control and hydroelectric power generation. Not only it’s the third tallest dam in the United States, it’s also the third tallest concrete dam in the Western Hemisphere. The three thousand-foot-long concrete gravity structure nowadays is a popular tourist spot as close to 140,000 people visit the site annually.

Lake Shelbyville Dam In Illinois

Lake Shelbyville Dam infographic

The one hundred eight feet high structure stretches over 3,025 feet long. Its structure includes earthfill and concrete. It’s buttressed by an internal steel framework to reinforce the strength of the construct. it impounds the Kaskaskia River and has five different parks around the site of the structure. Around Lake Shelbyville, there are five available marinas along with several campgrounds and resorts at the lakeside. Lake Shelbyville is also one of the deepest lakes in Illinois.

Brookvale Lake Dam In Indiana

Bridge over Joseph River

Shot of bridge over Joseph River in South Bend, Indiana on a gorgeous sunny day in spring.

©LeisureCowboy/iStock via Getty Images

The 181-foot-tall structure is at Brookvale Township in Franklin County, Indiana. It’s an embankment structure that helps with impounding the east fork of the Whitewater River. The embankment has a maximum capacity of 359,600 acre-feet.

Coralville Dam In Iowa

"Largest Dam" infographic for Coralville Dam in Iowa.
Coralville Lake is visited by 285 species of birds, and a small herd of bison lives there for educational purposes.

This Earth-fill structure opened in 1958. It created the artificial reservoir in Coralville Lake in Johnson County, Iowa. It’s a 132-foot structure that helps impound the Mississippi River. Nowadays, Coralville Lake has many recreational opportunities with eleven recreational areas, four beaches, three campgrounds, eighteen boat ramps, and seven trails that are twenty-nine miles long.

Cedar Bluff Dam In Kansas

Cedar Bluff Dam infographic

The Cedar Bluff Embankment is 202 feet tall, 12,560 feet long, and helps impound the Smoky Hill River. One of the purposes of the embankment is to help prevent excessive flooding in Kansas. It controls 445,095 acres-feet of flood water. The impounding of the Smoky Hill River created the Cedar Bluff Lake. The structure helps save water for irrigation since Kansas is a big agricultural state and their economy greatly depends on farming.

Dix River Dam In Kentucky

Louisville, Kentucky, USA skyline on the river.

Louisville, Kentucky, USA skyline on the river.

©Sean Pavone/Shutterstock.com

The Dix River Dam is a 287-foot-tall dam that helps impound the Dix River. It’s between Mercer and Garrard County, Kentucky. It’s more recognized for creating the popular Herrington Lake than it is for impounding the Kentucky River. Thankfully, it prevents excessive flooding of the river and generates hydroelectricity.

Toledo Bend Dam In Louisiana

The Toledo Bend Dam is the Largest Dam in Louisiana
The Toledo Bend Dam is the Largest Dam in Louisiana.

Toledo Bend is on the Sabine River between Louisiana and Texas. It is 185 feet tall and creates the Toledo Bend Reservoir, which is the largest man-made reservoir in the southern region of the United States. Toledo Bend is an earth-fill structure.

Harris Station Dam In Maine

Harris Station Dam infographic.

This structure impounds the Kennebec River in Maine. It is a 175-foot concrete gravity construct that helps produce hydroelectricity in the Northeast Somerset area. Harris Station is twelve miles away from Moosehead Lake. This structure was a part of the Indian Pond Project from 1952-1954.

Conowingo Dam In Maryland

Conowingo is the largest concrete gravity dam in Maryland.

This 94-foot-tall construct resulted in the creation of the Conowingo Reservoir. It’s at the lower part of the Susquehanna River near Conowingo Maryland. It sits nine miles from the Chesapeake Bay, forty-five miles from Baltimore, and five miles from the Pennsylvania border. It was first built with eleven turbine sites and has fifty-three flood control gates.

Wachusett Dam In Massachusettes

A beautiful shot of the Great Stone Dam in Massachusetts, United States

A beautiful shot of the Great Stone Dam in Massachusetts, United States

©Wirestock/ via Getty Images

The Wachusett Dam represents the Massachusetts entry on this list. The 205-foot-tall structure is a part of the Greater Boston Water System and a part of the Nashua River Watershed. When it was completed in 1905, it was the world’s largest public water supply reservoir in the world. The project created thousands of jobs for immigrants at the time. Its construction affected the surrounding areas as it destroyed homes, schools, and churches. Over four thousand bodies had to be dug up and moved into a new Catholic Cemetary.

The Hardy Dam In Michigan

A simple infographic of the construct.

This 120-foot-tall structure stretches over 2,600 feet along the Muskegon River. It has plenty of wildlife in the rivers and reservoirs created by the structure.

Rapidan Dam In Minnesota

People viewing construction site of Blue Earth Dam, Rapidan Township, Minnesota

People viewing the construction site of Blue Earth Dam, Rapidan Township, Minnesota

©Blue Earth County Historical Society, Public domain – License

The Rapdian/Blue Earth construct is an eighty-seven-foot-tall gravity concrete structure that impounds the Blue Earth River in the Rapidan Township. It was finished in 1910. Its purpose is to serve hydroelectric power generation for a power plant station nearby. The structure can be found just southwest of Mankato, Minnesota. There are parks, campgrounds, and river access along the reservoir banks and the structure’s site.

Sardis Dam In Mississippi

An infographic on The Sardis in Mississippi

The Sardis stretches over fifteen thousand feet long and stands at ninety-seven feet tall. The structure created the Sardis Lake and impounded the Tallahatchie River in Lafayette, Mississippi. This structure was a part of the Yazoo River Headwater Projects to help with flood control, especially alongside the Mississippi River. It has a hydraulic fill which helps grab soil below the construction site to form the Earth fill. This is a result of the Flood Control Act of 1936.

Table Rock Dam In Missouri

Brownville Bridge over the Missouri River on U.S. Route 136 from Nemaha County, Nebraska, to Atchison County, Missouri, at Brownville, Nebraska, aerial view in fall scenery with flooded river.

Brownville Bridge over the Missouri River on U.S. Route 136 from Nemaha County, Nebraska, to Atchison County, Missouri, at Brownville, Nebraska, aerial view in fall scenery with the flooded river.

©marekuliasz/Shutterstock.com

The Table Rock structure is a 220-foot-tall structure that stretches over 6,400 feet across the White River. It’s a popular fishing attraction for citizens at Branson, Missouri. Downstream from the site, the Missouri Department of Conservation operates a fish hatchery used to stock trout for another lake downstream, Lake Taneycomo.

Montana Hungry Horse Dam

Infographic of Hungry Horse Dam
Hungry Horse Dam is within Flathead National Forest and around 15 miles south of Glacier National Park.

This 564-foot-high behemoth is made with more than 2 million cubic yards of concrete. It helps with irrigation, flood control, recreational purposes, hydroelectric generation, and river regulation. Hungry Horse sits on the South Fork Flathead River in Northwest Montana. Hungry Horse helps with migrating fishes outward to the Pacific Ocean and the Columbia River Estuary.

Medicine Creek Dam In Nebraska

Medicine Creek Dam

The Medicine Creek Dam is made of earth and rock, and it has a concrete spillway.

©Ammodramus/ CC0, via Wikimedia Commons – License

The Medicine Creek Dam is a 165-foot-tall Earth-fill dam that impounds Medicine Creek. It’s at Frontier County, Nebraska. This structure impounds the Medicien Creke for flood control.

New Hampshire’s Moore Dam

Moore Dam and reservoir

Moore Dam and Reservoir in New Hampshire.

©AntiCompositeNumber, CC BY-SA 4.0, via Wikimedia Commons – License

The Moore Dam is a 178-foot-high, 2,920-foot-long embankment that impounds the Connecticut River. It is the uppermost part of the Fifteen Miles Fall Hydroelectric project which began in the early 1900s. The dam has a full surface area of 3,490 acres. This structure created the Moore Reservation, which is one of the most underdeveloped reservoirs in the New England area with little houses and business homes. TransCanada owns the reservoir side of the site and permits public access.

New Jersey’s Merrill Creek Dam

Infographic for the Merrill Creek Dam, New Jersey.
An infographic on New Jersey’s entry on this list.

The Merril Creek area is home to the water structure and the deep reservoir. It provides water to the power plants on the Delaware River. The Merril Creek Reservoir is designed to hold fifteen billion gallons of water.

New Mexico’s Navajo Dam

Navajo Dam / Navajo lake, San Juan County, New Mexico

Navajo Dam / Navajo Lake, San Juan County, New Mexico.

©James Orndorf/Shutterstock.com

The Navajo Reservoir is located in San Juan County, New Mexico. The dam is a 402-foot-tall embankment structure that helps impound the San Juan River. It’s a major feature of the Colorado River Storage Project, which emphasized regulating water resources across the upper Colorado River Basin.

New York’s Lewiston Dam

Rushing water of Niagra River

A picture of R\rushing water of Niagra River.

©RHartley/Shutterstock.com

The Lewiston Dam helps regulate the Niagra River water levels. It’s a 389-foot-tall structure that was built to replace a collapsed power structure in 1956. The construction of the dam resulted in twenty workers dying and over twelve million cubic yards of rock was removed. It helps return some of the water to Lake Ontario in Canada and uses thirteen generators.

North Carolina’s Fontana Dam

An infographic on the Fontana Dam

The Fontana Dam is a 480-foot-tall and has a length of 2,365 feet. It impounds the Little Tennessee River in North Carolina. It’s the tallest dam in the Eastern United States region and has a flood storage capacity of 513,000 acres-feet.

North Dakota’s Garrison Dam

Photo of a dam on a river. The dam is long and made of concrete. IThere is water pouring through the dam. in the foreground green tall prairie grass is growing

Photo of a dam on a river. The dam is long and made of concrete. There is water pouring through the dam. In the foreground green tall prairie grass is growing.

©Bob Pool/Shutterstock.com

The Garrison Dam is a 210-foot-tall embankment dam that impounds the Missouri River. It’s in the Mercer/McLean counties in Central North Dakota. The structure is 11,000 feet in length and is one of the six dams alongside the Missouri River.

William Harsha Dam In Ohio

The William Harsha infographic

Ohio’s largest water structure helps impound the Little Miami River. It is 200 feet high and 1,450 feet long across the Little Miami River. It’s a rock-fill structure that uses clay and earth elements to fix the cracks within the structure.

Oklahoma Broken Bow Dam

Broken Bow Dam infographic
Broken Bow infographic

The Broken Bow structure towers over the Mountain Fork River. It’s a 225-foot-tall construct that spans over 2,750 feet in length. The Broken Bow Lake was authorized by the Flood Act of 1958 and the lake has over 180 miles of shoreline. It provides a home for large trout and bass populations.

Oregon Cougar Dam

Portland, Oregon, USA Skyline

Portland, Oregon, USA skyline at dusk on the Willamette River.

©Sean Pavone/iStock via Getty Images

Oregon’s entry on this list is a 519-foot-tall rockfill hydroelectric structure that impounds the South Fork McKenzie River. It was fully completed in 1964 with two turbine generators and operates with the Blue River Dam. It also helps store and mitigate fish populations in different bodies of water across the Northwestern United States.

Raystown Dam In Pennsylvania

An infographic on the Raystown Dam

The 1,700-foot long, 225-foot-tall Earthfill structure helps impound the Raystown Branch Juniata River in Huntingdon County, Pennsylvania.

Scituate Reservoir Dam In Rhode Island

Sunrise at Scituate reservoir in winter

Sunrise at Scituate Reservoir in winter.

©nicholas katsaras/Shutterstock.com

The largest dam in the smallest state in America is located at the Scituate Reservoir. It’s a 100-foot-high earthfill structure that impounds the North Branch Pawtuxet River.

South Carolina’s Jocassee Dam

Lake Jocassee Dam is the Largest Dam in South Carolina

Lake Jocassee Dam is the Largest one in South Carolina. It created Lake Jocassee. The structure is a 385-foot-tall embankment and impounds the Keowee River. It has a capacity of 45,700 cubic feet per second. Since its inception in 1973, the structure has provided recreational opportunities for people thanks to Lake Jocassee. Many people go camping or fishing along the shorelines often.

Oahe Dam In South Dakota

Lake Oahe

Oahe Lake varies by deepness with shallower depths near the shoreline and some of the deepest spots near the Oahe Dam.

©Chadden Roggow/Shutterstock.com

South Dakota’s entry on this list is a 245-foot-high embankment that impounds the Missouri River. It’s just north of Pierre, South Dakota. The structure helps with irrigation, navigation, and hydropower generation. It was authorized by the Flood Control Act of 1944.

Watauga Dam In Tennessee

Overlooking the TVA Watauga Dam on a summer day at Watauga Lake in the Cherokee National Forest in Tennessee.

Overlooking the TVA Watauga Dam on a summer day at Watauga Lake in the Cherokee National Forest in Tennessee.

©iStock.com/Eifel Kreutz

Tennessee’s entry on this list is a 318-foot-high rockfill structure that impounds the Watauga River. Thanks to its creation, the rockfill dam helps with irrigation, and flood control, and provides many recreational opportunities.

Mansfield Dam In Texas

An infographic on Texas’s entry.

Texas’s entry is a 278-foot-high behemoth that helps impound the Colorado River in Texas. The structure was completed in 1941. Lyndon B. Johnson gained political support for Texas’s 10th Congressional District. because of his contributions to the structure.

Utah’s Flaming Gorge Dam

An infographic on Utah’s entry

This 502-foot-tall concrete arch structure is a sight to behold! It helps impound the Green River, which is a part of the Colorado River. It’s one of four storage units as a part of the Colorado River Storage Project which aimed to improve water storage throughout the Colorado River. The Flaming Gorge provides a wildlife home for many trout, rattlesnakes, bass, and catfish.

Vermont’s Waterbury Dam

Colorful aerial view of Waterbury Reservoir near in Waterbury Vermont during the fall.

Colorful aerial view of Waterbury Reservoir near Waterbury Vermont during the fall.

©John Couture/Shutterstock.com

The largest dam in Vermont belongs to the Waterbury Dam which regulates the Waterbury Reservoir. It stands at 187 feet tall and is 2,130 feet long. The initial purpose of the dam is to help impound the Winooski River due to its history of catastrophic floods. The Flood of ’27 caused the Winooski River to rise ten feet above water levels. Eighty-four people died due to the flood. The flood caused over 2.8 million dollars in damage. Today, it’s home to vast wildlife like geese, bears, snakes, turtles, and salamanders.

Virginia’s Upper Dam At Bath County Pumped Storage Station

Virginia’s entry is a part of a powerhouse plant. It controls the flow of the Back Creek and Little Back Creek. The upper dam is 460 feet tall and stretches over 2,200 feet long. The Bath County structure was developed in the 1970s. Bath County’s Pumped Storage Station is a giant battery of sorts as it can drain and store hydropower as needed. It also helps reduce the need for coal and nuclear plants so they can run efficiently.

Washington’s Mossyrock Dam

An infographic on Washington’s entry.

Washongton’s largest dam belongs to the Mossyrock Dam. It’s a 606-foot high concrete arch dam taht impounds the Cowlitz River. Since its inception in 1968, the structure generates electricity for nearby towns and counties. It received more electric turbines in 2006 to help with greater power generation.

West Virginia’s Pentwell Dam

An infographic on West Virginia’s entry.

Since its opening in 1966, the Summersville Dam has controlled flooding for the state. The 390 foot high rockfill structure impounds the Gauley River.

Wisconsin’s Hatfield Dam

Wisconin

Snow falls in Wisconsin in the winter months, with occasional drops occurring in November.

©Michael Tatman/ via Getty Images

The tallest dam in Wisconsin belongs to the Pentwell Dam. The Pentwell structure is the smallest on this list at 44 feet tall. It’s a structure that takes up over 23,000 acres and helps with power generation and flood control.

Buffalo Bill Dam In Wyoming

Infographic of Buffalo Bill Dam
Officials renamed it to honor William Cody, also known as Buffalo Bill, in 1946.

The massive Wyoming structure is three hundred twenty-five feet tall and is in the northwestern part of Wyoming. It’s a concrete arch-gravity structure that impounds the Shoshone River.

The photo featured at the top of this post is © Jim Vallee/Shutterstock.com


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About the Author

Justin is an A-Z Animals Writer that loves to cover places, unique natural disasters, and travel. He has eight years of experience as a writer in the medical and media fields. He wrote for the likes of VCU Health, theMSQshop, PayDay LA, and Comic Book Resources under the penname Jay Guevara. Although he's a full time writer, Justin graduated from Virginia Commonwealth University in 2019 with a Bachelors in Health, Physical Education, and Exercise Science with a background in Community Engagement. After spending over two decades in Richmond, Virginia, Justin now resides in the suburbs of Rancho Cucamonga, California. He's a dedicated gymrat. He's also a two-time poetry author who's influenced by rappers Joe Budden and IDK along with Dante Alighieri.

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