The 10 Most Dangerous Rivers in the United States

1. Red River of the South

The Red River of the South flows 1,360 miles through Texas, Oklahoma, Arkansas, and Louisiana. The strong rushing currents of the river can easily carry away people who fall in. The river gets its name from the large quantities of red soil that the river carries during flood periods.

While this soil gives the river a unique look, it also makes its waters murky. Due to this, it can be difficult to search for victims who fall in the water. The river’s depths also change frequently and without warning, making it all the more treacherous to enter.

2. American River

The American River is a 30-mile body of water in California. It is a popular spot for whitewater rafting but even those entering the water in a raft should exercise caution.

Earlier this year ABC 10 News officials noticed a trend that involved challenges to jump into the American River. Officials in the area warned people not to partake in this trend, as two men were swept away in the American River’s currents earlier that year. One body was recovered and the other man is still missing.

3. Arkansas River

The Arkansas River flows through Colorado, Kansas, Oklahoma, and Arkansas over a course of 1,460 miles. This body of water is known for its rapids, making it a popular destination for white water rafting.

However, the Arkansas River can be extremely dangerous and includes Class IV rapids. While reputable white water rafting companies make safety their top priority, bodies of water like the Arkansas are unpredictable. As of August 2023, four deaths were reported on the Arkansas River that year, according to Summit Daily.

4. Colorado River

The Colorado River frequently makes its way into lists of the most dangerous rivers in the United States. This body of water spans 1,450 miles through seven states—Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona, and California.

The Colorado River moves quickly and water levels get quite high. Due to this, numerous drownings occur in this body of water, including skilled swimmers and experienced rafters. Five deaths and three missing people were reported on the Colorado River for the year 2023, as of August.

People who fall into the Colorado River are at risk of flush drowning due to the water’s fast currents. According to Team River Runner, flush drowning occurs when a swimmer is moved downstream and repeatedly dunked underwater or hit by waves, causing them to aspirate water.

Additionally, the Colorado River features runoff from snowmelt, meaning that its temperatures commonly drop as low as 42°F. This puts anyone in the river at serious risk of hypothermia and death.

5. Ohio River

Rivers can be dangerous for a number of reasons, from fast currents to freezing temperatures to dangerous wildlife. However, the Ohio River, which flows for 981 miles in the Midwest and Southern United States, is treacherous for a different reason.

The Ohio River is frequently referred to as the most polluted river in the United States. According to Green Matters, a 2020 report that analyzed the EPA’s Toxic Release Inventory found that more than 40 million pounds of toxic substances were released from industries into the Ohio River basin.

This is more than any other major waterway in the United States. Additionally, a 2023 train derailment in East Palestine, Ohio sent toxic materials into the Ohio River, resulting in the deaths of thousands of marine life.

6. Rio Grande

The Rio Grande forms part of the border between the United States and Mexico and flows for 1,885 miles. Due to the river’s location, many migrants have attempted unsafe journeys to cross its waters.

Unfortunately, this has led to hundreds of deaths in the Rio Grande, mostly from drowning in its turbulent currents, reports Oregon Public Broadcasting. Due to this, Texas Governor Greg Abbott announced plans to install a stretch of buoys on the river to prevent migrants from attempting to cross the river and putting themselves at risk of drowning.

7. Merrimack River

One of the most dangerous rivers in the United States is located in New Hampshire. The Merrimack River runs for 117 miles through the Granite State before turning southward into Massachusetts and emptying into the Gulf of Maine.

According to the Newbury Port News, the Merrimack River has earned a reputation as one of the most dangerous rivers for mariners in the United States. At the mouth of the Merrimack, a large amount of water surges through a rather small, funnel-like area.

This creates strong currents during outgoing tides, as well as unpredictable eddies and swells. “Standing waves” at the mouth of the Merrimack River are powerful enough to flip boats and jetties have been known to slice open the hull of ships.

The news outlet reports one incident in 2008 when water from swells sank an overloaded 17-foot Stingray. Thankfully nearby boats were able to rescue all nine passengers.

8. Potomac River

The Potomac River is frequently listed among the most dangerous rivers in the United States. This body of water flows through Virginia, West Virginia, Maryland, and the District of Columbia for 405 miles.

Despite being one of the shorter rivers on this list, the Potomac can be quite deadly. According to National Park Services, part of the danger of the Potomac comes from the fact that its calm-looking surface can disguise invisible underwater currents (and whirlpools), which move downward and can pull a person to the bottom of the river.

People can become trapped 15 to 30 feet below the surface or under submerged rock ledges. The Potamic River is so dangerous that swimming and wading between Great Falls and the southern Maryland/DC line are illegal. NPS warns visitors against even sticking their feet in the water.

9. Mississippi River

The mighty Mississippi flows for 2,340 miles, passing through 10 states in the American Midwest and Southeast. The Mississippi River is known as one of the most dangerous rivers in the United States for many reasons.

First, the Mississippi River flows quite quickly in some places and is known to have strong undercurrents. According to National Park Services, the river flows at an average surface speed of around 1.2 miles per hour at its headwaters. In other places, the Mississippi moves at speeds of up to 3 mph.

While some people do swim in certain stretches of the Mississippi River, this body of water poses certain health risks. NPS writes that stretches of the Mississippi exceed water quality standards for mercury, bacteria, sediment, PCBs (polychlorinated biphenyl), and nutrients. This makes the water unsafe for fishing and swimming.

Finally, the Mississippi River is teeming with life and some of its critters pose a potential threat to humans. The Mississippi is one of the most snake-infested rivers in the United States, though only a few species that live along its banks are venomous.

American alligators are one of the most dangerous creatures that lurk below the surface of the Mississippi River. Incredibly, incidents of bull sharks entering the river have also been reported.

10. Kern River

With nicknames such as the “Killer Kern,” it’s hard not to rank the Kern River as the most dangerous in the United States. Located in California, the Kern River flows for approximately 165 miles.

A number of safety concerns surround the Kern River. This body of water is known for its swift and powerful currents, which have claimed the lives of many who enter it. In fact, a sign at the mouth of Kern Canyon warns visitors: “Danger. Stay Out. Stay Alive” and tallies the number of deaths in the river at 325 people since 1968.

Additionally, in the spring and summer, snow melt from the Sierra Nevada Mountains flows into the Kern River. According to the Missoula Current, this causes the river’s water temperature to drop — sometimes as low as 38°F. In water temperatures below 40°F, serious injury can occur in just a few minutes, and death from hypothermia may occur in well under one hour.