11 Most Dangerous Rivers in the US (Updated)

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Rogue River, Oregon
Although some areas of rivers have safeguards, in other areas it’s the visitor’s responsibility to ensure their own safety. Bureau of Land Management Oregon and Washington / CC BY 2.0

Deaths on rivers are almost always accidental and typically result from unforeseeable conditions or poor preparation. Therefore, the number one thing a river-goer can do to avoid injury or death on or near a river is to prepare, which requires both appropriate supplies and a robust understanding of the type of dangers that may be encountered in the specific river they are visiting. These dangers include currents, water depth, debris in the water, extreme temperatures, water quality, and weather.

In many cases, areas of rivers open to the public in state or national parks have safeguards to prevent visitors from encountering dangerous situations. In others, safety is entirely the visitor’s responsibility and should be taken seriously to prevent serious injury or death.

This list will discuss several rivers in the United States that are notoriously dangerous and describe factors that increase risk when visiting them. Despite the number of waterways covered in this list, it is not exhaustive, and almost any major river can become dangerous if conditions are right. For example, flash floods can present an immediate and unpredictable hazard for river-goers. Huge quantities of fast-flowing water have the power to move cars, destroy buildings, and knock down bridges; a small boat on a river or a group of hikers may be especially vulnerable in the event of a flash flood. As a result, visitors should aim to enjoy rivers when the weather is clear and adhere to local weather warnings.

Statistics On River Accidents

Life jackets
Many river accidents occur due to failure to wear personal flotation devices. Kingsport Humor / CC BY 2.0

According to American Whitewater, an organization that protects and restores North America’s whitewater rivers, most river accidents as of July 2020 occurred on private vessels. These deaths are primarily attributed to drowning, failure to wear personal floatation devices (i.e. life vests), or when a ship is overturned and pins an individual against another structure or underneath the water.

According to the CDC (2011 – 2020), drowning is particularly deadly to children and remains the leading cause of death for children ages 1 – 4, and it is the second leading cause of death for children ages 5 – 14. While most drownings for children aged four and under occur in the home, among children aged 5 – 14, 40% of drowning deaths occur in natural bodies of water.

Impairment due to alcohol consumption or improper preparation (i.e. lack of floating vests or rescue devices) also contributes significantly to water-related deaths.

Deadliest Rivers in North America & USA

Kern River

Kern River
The Kern River is known for its strong currents which are some of the strongest in North America. Qwert üpoiuz, CC BY-SA 4.0, via Wikimedia Commons

The Kern River is a whitewater river that cuts through the Sequoia National Park and National Forest. It is a popular destination for hikers, campers, and thrill seekers looking to experience the river’s temperamental waters that flow through wetlands and over waterfalls. The river’s currents are among the strongest in North America, with consistent Class IV and V rapids and waterfalls. This river also tends to form strong vortices or sections where the water spins, which can disorient rafters and flip rafts.

The Forks Run is a popular whitewater rafting segment of the Kern River that services 15 people daily during its season, extending from May 15th to September 15th annually. It is approximately 14.6 miles (23.5 km) long. While rafting the Kern River can be an exciting experience, it should only be undertaken by experienced rafters. At the mouth of the river is a sign with a running death toll warning visitors of the 325 lives lost to the river since 1968.

Potomac River

Great Falls, Potomac River
Swimming freely in the Great Falls area of the Potomac River is not permitted as it’s too dangerous. Jan Kronsell / CC BY-SA 3.0

Starting in Fairfax Stone, West Virginia, and ending in Chesapeake Bay in the District of Columbia, the Potomac River is a large river that marks the boundary of several northeastern states. Not all river sections are dangerous, but those like the Great Falls of the Potomac can be deadly. Swimming freely in this area is illegal and strong currents are known to pull kayakers (and swimmers) under. These currents are often invisible and can sweep individuals below the water’s surface, where they may become trapped in debris and drown. In dangerous river sections, drowning is the leading cause of death. American Whitewater lists at least 48 accidents in the Potomac, several of which have resulted in injury or death.

Poor water quality can also harm humans and is another reason swimming in the Potomac is illegal. Eating fish from the river is also prohibited due to pollutants that contaminate aquatic life in the river. High levels of bacteria and algae are also present in the water, which can make swimmers and waders ill. The Potomac is a huge river, and not all regions are dangerous, so it is important to adhere to local safety guidelines and avoid dangerous or contaminated water.

Mississippi River

Map showing Mississippi River
The Mississippi River is a huge waterway that almost cuts the United States in half. Shannon1, CC BY-SA 4.0, via Wikimedia Commons

Nearly cutting the United States in half, the Mississippi is a massive river that has played an important role in American history as a major navigable waterway that enabled settlers to colonize the heart of North America. Today, it is a significant shipping channel that powers the economy in the American Midwest and remains one of the world’s largest rivers. Historically, the river was carved into the North American landscape, shaping the land within its watershed and building terrain at the Mississippi River Delta. The river has since been “tamed” by humans through a complex levee system that keeps the river from flooding its banks but has also increased the speed at which water flows downstream.

Like most large rivers, the Mississippi harbors strong flows and deceptively powerful undercurrents that can sweep swimmers under. In areas where water flow is slow, swimming without fear of drowning may be possible, but pollution remains a health risk. Sources of pollution range from road salting to agricultural runoff that can expose swimmers to a range of toxic chemicals and encourage the growth of harmful algal blooms. The effects of these chemicals can be seen in the Gulf of Mexico, where agricultural runoff combined with severe flooding has resulted in a widespread dead zone where algal blooms choke out plant and animal life.

Merrimack River

Merrimack River
Some parts of the Merrimack River are more dangerous than others. Since 2010, there have been reports of 31 deaths on the river. Bookwormr98, CC BY-SA 4.0, via Wikimedia Commons

Starting in New Hampshire and emptying into the Atlantic Ocean in Massachusetts, the Merrimack River is well-known as a serene and peaceful waterbody. Its watershed covers approximately 5,010 square miles (about 12,980 square km) and the river provides drinking water for over 700,000 people, supports agriculture, and creates habitat for wildlife. In addition to its economic and environmental importance, the Merrimack River also provides recreational opportunities for visitors looking for boating, kayaking, fishing, and swimming opportunities.

Visitors should take caution when visiting the river responsibly, as swift currents and harsh undercurrents are known to drown free swimmers. Some river segments are more dangerous than others, such as the bend from Boscawen Boat Launch to the Hannah Dustin Memorial in New Hampshire. Reportedly 31 people have died on the Merrimack since 2010, and several more have suffered river-related injuries. The Merrimack River is known for being unpredictable and potentially dangerous, so proper precautions should be taken when visiting the river.

Rio Grande

Rio Grande River
The Rio Grande River defines the boundary between Mexico and the US and has unfortunately claimed the lives of more than 4,000 migrants trying to cross. Bureau of Land Management, Public domain, via Wikimedia Commons

The Rio Grande has a unique position along the United States’ southern border, where it defines the boundary between Mexico and the U.S. As a result, migrants crossing the Rio Grande and traveling into the US make up a disproportionate number of drowning deaths in this river. Approximately 4,000 individuals have died attempting to cross the Rio Grande since 2014, proving that crossing the Rio Grande is a dangerous feat. The river is also hazardous to residents and visitors. Non-migrant drownings and rafting deaths also add to the river’s fatalities.

Despite the staggering number of fatalities at the Rio Grande, it can be enjoyed for its beauty and recreational opportunities. The river’s rapids range from class I to IV, which can be exciting for visitors. New Mexico and Colorado adventure companies help visitors enjoy this beautiful river safely.

Naugatuck River

Naugatuck River
The Naugatuck River was used to discard industrial waste and sewage, leading to the introduction of dangerous chemicals in the water. Joe Mabel, CC BY-SA 3.0, via Wikimedia Commons

The Naugatuck River is a major river in Connecticut and extends about 40 miles (64.4 km) from Torrington, CT, to a junction where it meets with the Housatonic River. Eventually, the two rivers end in the Long Island Sound. The river plays a role in American history as a major navigable river, is a source of hydroelectric power, and was commonly used to discard industrial waste and sewage. These sources of pollution have led to the introduction of dangerous chemicals like phthalates and petroleum byproducts, which harm aquatic life and pose a danger to human health. Other risks to humans include strong currents and abundant debris. Entrapment in rubble or strong currents can tire and drown free swimmers or individuals knocked off overturned vessels.

Despite its reputation as a dangerous and polluted river, it is currently fishable and boatable throughout its length. Recently, local and government-led efforts have been established to clean up the river, making it safer for visitors and improving the habitat in and around the water.

Colorado River

Colorado River
Some sections of the Colorado River are labeled Class VIII to Class X due to some difficult passages created by the Grand Canyon. Smtunli, Svein-Magne Tunli – My photo gallery, CC BY-SA 3.0, via Wikimedia Commons

Starting in the majestic Rocky Mountains and ending in the Gulf of California, the Colorado River is a beautiful and commercially important water feature that snakes through the picturesque Grand Canyon. In late spring, rafters and tourists flock to the Colorado River to safely enjoy its swift currents. While the river can be safely enjoyed by observing proper safety etiquette, it does harbor some dangers.

The Colorado River has similar dangers as previously mentioned–pollution, debris, dangerous rapids, and freezing, making hypothermia possible for unprepared swimmers or rafters. Class III rapids and above are common and can knock rafters into frigid waters. Sections of the Colorado River are even labeled Class VIII to Class X due to the difficult passages created by natural passages in the Grand Canyon. During the spring, snowmelt increases the river’s height, increasing the danger of drowning.

Kaweah River

Kaweah River
The Kaweah River is home to harmful algal blooms and dangerous bacteria, so it is not advised to drink from the river. Daniel Mayer (mav), CC BY-SA 3.0, via Wikimedia Commons

From the Sierra Nevada mountains to Lake Kaweah, the San Joaquin Valley eventually runs the Kaweah River. Interestingly, the Kern River also feeds into this valley. Three separate forks comprise the Kaweah River: the Northern, Southern, and Middle.

The Kaweah River harbors some intense Class III to IV+ rapids that attract visitors searching for an exciting rafting experience among the beautiful Sierra Nevada mountains. While the river can be dangerous for children, inexperienced swimmers, or intoxicated persons, the current risk to individuals is harmful algal blooms and hazardous bacteria that thrive in the river. As a result, visitors and locals should refrain from drinking the river water and heed local community and government warnings about water conditions.

Gauley River

Gauley River
The Gauley River, which stretches for about 104 miles, is known for its whitewater rapids and breathtaking landscapes. Ken Thomas, Public domain, via Wikimedia Commons

The Gauley River meanders through deep canyons, lush forests, and rocky gorges, providing breathtaking views for those exploring the area. It stretches for approximately 104 miles (167 kilometers), and the Gauley River watershed covers an area of about 1,422 square miles (3683 square kilometers). It flows through West Virginia and merges with another river to create the Kanawha River.

Known for its challenging whitewater rapids and scenic beauty, it is a popular destination for outdoor enthusiasts and thrill-seekers, particularly for whitewater rafting and kayaking. One of the reasons the Gauley River is so famous for whitewater rafting is due to its controlled water release schedule. The Army Corps of Engineers manages the water releases in the fall, typically during September and October. These releases increase the river’s flow and create optimal conditions for challenging rapids.

Salmon River

Rafter on Salmon River, Idaho
Salmon River is home to a variety of rapids that attract rafters of all skill levels. Ryanx7, CC BY-SA 3.0, via Wikimedia Commons

The Salmon River flows through central Idaho, originating in the Sawtooth and Lemhi Mountains and eventually joining the Snake River near Hells Canyon. It is the longest free-flowing river within one state in the United States, covering approximately 125 miles (201 kilometers). The North Fork to Corn Creek region is designated for recreational purposes, whereas the remainder of the river is considered “wild.” This segment flows through diverse landscapes, including deep canyons, pristine wilderness, and rugged mountains. The river corridor offers breathtaking vistas, with cliffs, gorges, and evergreen forests, creating a visually stunning backdrop.

The river offers a variety of rapids, ranging from Class II to Class IV, providing both thrilling experiences for adrenaline seekers and milder stretches for beginners and families. The Salmon River’s whitewater attracts rafters from all skill levels, offering exciting adventures and stunning natural surroundings. The “River of No Return” segment presents significant challenges for boaters and rafters. It has powerful rapids and remote areas where rescue can be difficult. The river’s ruggedness and unpredictable nature make it a dangerous waterway.

Columbia River

Columbia River
The Columbia River is dangerous for swimmers and rafters as it is prone to sudden weather changes that can create dangerous conditions. Doc Searls from Santa Barbara, USA, CC BY 2.0, via Wikimedia Commons

The Columbia River is renowned for its powerful currents, which provide hydroelectric power to millions of Americans along its banks. A series of dams built along its course, including the Grand Coulee Dam and the Bonneville Dam, harness the river’s flow to generate electricity. The hydroelectric facilities on the Columbia River have played a significant role in powering the region’s cities and industries, supporting their growth for centuries. The river and its tributaries also serve as critical spawning grounds for anadromous fish migrating from the ocean to their freshwater birthplaces to reproduce. The salmon runs of the Columbia River, which last from March to October, have cultural and ecological significance and are closely monitored and managed to maintain their sustainability.

While the Columbia River offers numerous recreational opportunities and economic benefits, it also poses certain dangers that individuals should be aware of. The Columbia River has swift currents and dangerous undertows, which may surprise recreational swimmers. It is prone to sudden weather changes and can create treacherous conditions for boaters and swimmers. The freezing water temperatures, abundant debris, and other hazards make this river particularly dangerous for swimmers and rafters.

Ways to Prevent River Incidents 

Boat on river
An experienced person should always operate the watercraft and must remain alert and active. Ed Dunens / CC BY 2.0

The most reported incidents of accidents around or in rivers in 2020 occurred in rivers with class I rapids which, compared to higher-class rapids, are not very dangerous if the proper precautions are taken.

These precautions include but are not limited to:

  1. Supervise children and ensure that everyone in your party knows how to swim and is aware of potential hazards in the water.
  2. Wear a life vest or protective floatation equipment, or PFE, on any watercraft.
  3. Operate watercraft responsibly and with caution. Ensure an experienced party member operates the watercraft and remains alert and active throughout the trip.
  4. Avoid alcohol & understand the effects of prescription drugs. In 2022, alcohol use resulted in the most deaths out of any other contributing factor regarding aquatic accidents. Inexperience and speeding resulted in the most injuries.
  5. Have a plan for if an accident occurs. Some important equipment or skills to bring to a river include a rescue beacon, first aid and knowledge of first aid, and how to contact the nearest authorities for assistance if needed.
  6. Understand your limits.
  7. Be aware of the weather in your area and possible unpredictable weather events that may influence the speed and behavior of the water.

What Other Factors Make a River Dangerous?

Niagara Rapids
Rapids can make rivers even more dangerous and may become more severe depending on the weather. Tanbir Ahmed, CC BY-SA 3.0, via Wikimedia Commons

Rapids are sections of rivers with fast-flowing and shallow waters. These conditions often produce white peaks, commonly referred to as whitewater rapids, and whitewater rafting is a popular thrill-seeking activity in these rivers. The severity of rapids varies from river to river and can be exacerbated by weather.

To provide river enthusiasts with an idea of the types of rapids present in a river, the International Scale of River Difficulty was developed by the American Whitewater Association to classify the severity and type of rapids present in a river on a scale of I to VI. Several factors are considered when grading rapids, including the water’s speed, the severity of waves and riffles, drops and land features that make a river difficult to traverse, the visibility and ease of avoiding debris in the water, the risk of injury, and the ease of getting assistance should visitors find themselves in trouble.

While these rivers are considered dangerous, they can be navigated safely with proper precautions, experience, and appropriate equipment. However, it is always recommended to consult local authorities, river guides, and experts before exploring challenging waterways.

Keyla P
About the author

Keyla P

I have a bachelor’s degree in Natural Resources focusing on Wildlife Ecology and a minor in Entomology. I am also an award-winning student researcher with five years of experience with wildlife-related research.

Read more about Pond Informer.

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