10 Most Dangerous & Deadly Lakes in the USA (Ranked) - Pond Informer (2024)

Time spent in and around the water swimming, fishing, and boating is a summertime staple for millions in the United States, and for good reason. Considering how beautiful and accessible these bodies of water are, it’s no wonder that lakes are some of the most popular destinations.

But as peaceful as lakeside life may be, these still waters hold hidden dangers, and hundreds of lives have been claimed. With the possibility of drowning, poisoning, suffocation, and more, deadly possibilities can be found in every lake.

This article will explore the dangers of 10 of the deadliest lakes throughout North America, such as treacherous weather, dangerous animals, and even toxic gas.

1) Lake Michigan

With over 150 deaths since 2002, Lake Michigan is considered by many to be the most deadly lake in North America. Drownings are typically blamed on Lake Michigan’s famous undercurrents and rip currents, but these are not the only culprits.

A variety of dangerous currents and waves can be found in the lake due to its unique features. Because many structures are flush with the lake floor, they are surrounded by currents. Swimmers are easily pulled into potentially dangerous locations, such as sharp rocks or areas that are difficult to navigate.

Due to its shape, Lake Michigan also has meteotsunamis and powerful standing waves known as seiches. These waves are able to tower 10 feet, as with a 14-foot seiche in nearby Lake Erie which claimed the lives of 78 people in 1844. Many seiches are small and imperceptible, but these are equally deadly. A seiche oscillating at only two feet tall was able to drag under seven swimmers in 2003.

Regardless of how beautiful its waters are, boaters and swimmers should take caution when navigating this potentially treacherous lake.

2) Horseshoe Lake, California

Not to be confused with its Illinoisan namesake, Horseshoe Lake is a small body of water found within the Mammoth Mountain Ski Resort with a deadly secret. Mammoth Mountain is an ancient lava dome formed by a series of explosions from roughly 110,000 years ago to 57,000 years ago.

The lava from the active volcano this mountain sits atop is not the cause of the numerous deaths associated with the region. Instead, magma shifts in 1989 opened up channels for volcanic gas to continually surface through vents known as fumaroles. After a massive number of tree-deaths began to occur around the lake in the 90s and a patrol officer fell ill, locals and scientists began to get suspicious.

By placing continuous flow instruments (CFIs), scientists were able to confirm that toxic hydrogen sulfide and carbon dioxide were seeping from nearby fumaroles and gathering around the lake. As illustrated in the tragic death of three ski patrol members in 2006, high levels of CO2 are able to cause unconsciousness and death at levels as low as 10 – 20%, and Horseshoe Lake can have CO2 levels as high as 90%.

Though the lake is surprisingly safe to swim in during the summer, deaths are reported almost annually during the winter months. Researchers and the local government monitor CO2 levels with CFIs throughout the year, and it appears that levels of this volcanic gas aren’t lowering any time soon.

3) Lake Champlain

At over 500 square miles, Lake Champlain is as large as it is beautiful. But underneath its surface, something deadly and quite literally alien lurks. Along with a rich native ecosystem, Lake Champlain is host to a swarm of non-native sea lampreys. These invasive parasites can grow to an impressive two feet in length and feed on their victims in an almost Lovecraftian manner. By using their suction-cup mouths and circular rows of sharp teeth, sea lampreys are able to feast on the juices of local fauna by burrowing into them and are even able to take down fish as large as monstrous salmon. This has resulted in a massive decline in native fish populations and significantly disrupted all levels of the local ecosystem.

While many scientists do not believe lampreys would attack or prey on humans, a diver infamously reported an attack in 2018, drawing the attention of freshwater detective and biologist Jeremy Wade. Although he was unable to verify these attacks on his show, Wade was able to track several massive lampreys and was even bitten by one in the process.

The lamprey population in these waters has been successfully reduced by chemicals known as lampricides, which specifically target lamprey larvae by using a salt known as TFM, which their bodies are unable to eliminate like other organisms. Although there is hope that sea lampreys can be gradually eradicated, many swimmers take care to avoid Lake Champlain’s depths.

4) Jacob’s Well, Texas

Despite being only 12 square feet at its surface, Jacob’s Well is a popular local and tourist swimming spot, beloved for its cool, crystal clear waters. As a perennial karstic spring, Jacob’s Well has a continual flow of freshwater pushed out by the Trinity Aquifer 140 feet below, and even historically gushed into the air!

The deep waters and lack of footholds in the lake are dangerous enough for poor swimmers, but most drownings in this lake have another cause. Many divers have been lured into Jacob Well’s intricate maze of underwater caves, and this cave system has been extensively explored and documented by divers in the Jacob’s Well Exploration Project.

Not only are the fascinating underwater structures a point of interest, but Jacob’s Well also houses a variety of fish, turtles, and even the cave-dwelling Fern Bank salamander. Unfortunately, inexperienced open-divers have also been drawn to this underwater labyrinth, resulting in eight reported fatalities between 1964 and 1984.

After officials sent the San Marcos Area Rescue Team (SMART) to recover these bodies, it was declared illegal for anyone but designated professionals to dive into Jacob’s Well. Even so, it is not unheard of for professional divers to come upon more recent remains, as open-divers are often curious about the depths of this gorgeous lake to this day.

5) Lake Mead, Nevada & Arizona

As the largest man-made reservoir in the entire United States, Lake Mead is as popular of a recreation area as it is dangerous. Since its formation in the 1930s, Lake Mead has been responsible for over 300 drownings, and the surrounding Lake Mead National Recreation Area has been named the deadliest park in the United States, with over 250 deaths in the last decade.

Despite its once astonishing size, Lake Mead is rapidly drying up due to compounding drought and climate change, making it at risk of becoming a “dead pool.” Not only does this create an increasingly unpredictable waterscape, but shallow waters and high winds have also resulted in unfortunately ideal conditions for boats to capsize in.

As water levels continue to drop, human remains have begun to emerge at a startling rate, with 5 bodies being discovered between the months of May and August 2022 alone. Most recovered bodies are assumed to be the result of accidental drownings, but in some cases, such as when skeletal remains were found in a steel barrel, more homicidal origins have been assumed.

6) Mono Lake

Mono Lake is an incredibly unique Californian lake that has been around for over 1 million years. This ancient lake is known as a saline soda lake, meaning its millennia of salt and mineral buildup has made it 2.5 times saltier than the ocean and incredibly alkaline to boot. It is surrounded by massive salt towers known as tufas, and several of these jut out of the water throughout the year. It lacks any real outlet, and at one point, Los Angeles diverted streams away from it, lowering water levels and increasing this concentration.

The high level of salts and chemicals found in Mono Lake creates a unique fishless ecosystem home to only flies, brine shrimp, algae, and the birds that feast on them. In particular, it has a significant buildup of arsenic, an acutely toxic compound, and is home to arsenic-loving bacteria.

This poisonous water is easy to ingest or even drown in due to the high wind speeds surrounding the lake, which often prevent any sort of rescue measures.

7) Onondaga Lake, New York State

Prior to heavy urbanization, Onondaga Lake was a sacred body of water in Onondaga territory and a choice vacation resort due to its natural beauty. In the early colonial years, factory owners ignored this lake, but industrialization eventually took hold of the area in the 20th century.

This led to a rapid influx of industrial runoff and waste along with sewage wastewater, resulting in massive algal blooms and their consequent biotoxins. Along with these biotoxins, highly toxic chemicals such as mercury that were dumped in Onondaga Lake accumulated, and swimming and fishing were both banned by the 1970s.

Lake Onondaga is no longer as polluted due to intensive cleanup efforts since the 1970s, but swimming is still banned and advisories have remained on sport fishing since 1984.

High mercury levels remain a danger for swimming and require regular testing, and it will likely be a long time before swimmers can freely inhabit these waters. Even so, Onondaga Lake is still considered one of the most successful environmental restoration projects of all time and has earned awards from Audobon and the WEDA Annual Safety Award.

8) Lake Erie

Despite being one of the Great Lakes, swimmers are unable to enjoy Lake Erie for much of the year. Since the 1960s, agricultural and urban runoff of nutrients such as nitrogen and phosphorus has spurred annual algal blooming. This abundance of nutrients, combined with other climate-related factors such as increasing temperatures, low water influx, and high winds, have contributed to this unique, up to 10,000 square-kilometer phenomenon.

From July to October, the middle of Lake Erie is covered in a layer of algae that blocks out light and obstructs gas exchange at the water’s surface. Dead algae regularly sink to the bottom of Lake Erie’s shallow depths, where bacteria rids the water of any remaining oxygen to digest it. This huge area, known as a hypoxic zone or dead zone, is unable to be inhabited by any sort of aquatic life.

Although fish are able to flee and remain in the lake shallows during the summer, any immobile life, such as mussels, cannot inhabit much of the lake without quickly dying off. Not only is the dead zone dangerous to wildlife, but biotoxins are secreted in high amounts by the bacteria that thrive in this hypoxic environment.

9) Lake of the Ozarks, Missouri

Considering it’s the home of bears, bobcats, four venomous snake species, and more, you’d be correct in assuming the Lake of the Ozarks is a pretty dangerous lake. But believe it or not, the majority of deaths in this Missouri lake are actually attributed to boating accidents.

The Lake of the Ozarks ranks first in the nation for boating accidents, many of which have proven to be fatal. Although drinking and boating is a federal and state crime, the Lake of the Ozarks is known for its parties and celebrations, meaning it has an intense drinking culture. In particular, the lake is known to be filled with drunken boaters on holidays such as Memorial Day weekend.

Intoxicated boaters can easily hit other vehicles, but lone swimmers are the typical victims of fatal accidents. On top of this, the Lake of the Ozarks has no speed limit during the day, and its 30 MPH speed limit at night is still fast enough to be dangerous to everyone involved.

10) Lake of Three Fires, Iowa

The Lake of Three Fires is a beautiful lake in Southwest Iowa beloved for its great natural beauty and various attractions. Unfortunately, this famous destination was temporarily closed in July 2022 due to a reported fatal case of primary amebic meningoencephalitis caused by Naegleria fowleri. Extensive testing by the Iowa Department of Health and Human Services (HHS) and the Department of Natural Resources (DNR) confirmed the presence of this amoeba in the Lake of Three Fires shortly after.

Naegleria fowleri is a naturally occurring amoeba that thrives in warm freshwater but has the ability to enter the human body through the nose in certain situations. After entering the body, Naegleria fowleri will begin feasting on brain tissue, resulting in seizures, hallucinations, swelling, and typically, death.

Naegleria infections are as rare as they are deadly, with only 143 known infections from 1962 to 2021 and a mortality rate of over 97%. Despite this, Naegleria can be found in almost any body of freshwater, especially in southern states. It is unknown why infection occurs, but it can be prevented by wearing nose plugs when swimming in lakes, keeping your head above water, and avoiding kicking up sediment.