Drowning Danger in Yosemite National Park’s Waters
Yosemite has many wild waterfalls, rivers and streams, causing visitors who are unprepared and don't heed the posted warning signs to get into trouble.
Your Yosemite vacation should be all about having fun in the great outdoors. But remember that Yosemite National Park truly is a wild place, meaning that sometimes visitors who are unprepared and don’t heed the posted warning signs can get into trouble and possibly drown. In an average year, Yosemite park rangers conduct around 250 search-and-rescue operations, many of them at streams, lakes and waterfalls. So, take time out now before your trip to learn about the park’s water safety hazards. That way, Mother Nature won’t catch anyone in your family by surprise during your Yosemite adventures!
Swimming in Yosemite National Park is a popular activity, especially after early summer. Ask at park visitor centers and information stations about safe local swimming spots nearby before you get in the water. Popular swimming holes are found along the Merced River in Yosemite Valley and at Wawona in the southern area of the park, as well as at a few places on the Tuolumne River (except at Hetch Hetchy reservoir, where swimming is prohibited).
Keep in mind that Yosemite’s streams and rivers may be running too fast and furiously for safe swimming until mid-summer. The valley’s Merced River can be dangerous to enter in June, when the waters are still chilly and are at high levels due to snow melting up in the mountains. Even strong swimmers can easily be swept off their feet and pinned down by strong currents, whirlpools and boulders in the icy waters of Sierra Nevada mountain streams and rivers.

Streams and rivers can be hazardous to hikers, too. Always exercise good judgment when deciding whether to make a water crossing on the trail, especially because otherwise gentle streams can become a torrent during the high country’s snowmelt during late spring and early summer. Rocks in and around streams are often extremely slippery. Once you start to cross, the water may actually be running deeper than it looked when you were standing on the banks. When in doubt, stay out.
In the below video, listen to Matthew Wolfe tell the story of him and his brother trying to cross Mirror Lake in 2012. The water seemed calm but it was deeper than it looked and then Matthew’s brother was pulled into the rapids downstream. Matthew managed to help his brother to a protruding rock in the middle of the rapids. Their story had a happy ending facilitated by Yosemite Search and Rescue. But that’s not always the case. Overall, drowning accounts for 25% of deaths in U.S. national parks.
Among the most common causes of accidental injuries and occasional deaths in Yosemite are water hazards. Most drownings happen when visitors decide to take a dip above a waterfall, then get caught by powerful currents and swept over the top of the falls. This was almost the case in 2013 when Alec Smith leapt over the protective barrier at the top of Vernal Fall on the Mist Trail. He did so just in time to save the life of a young boy caught in the Merced River’s turbulent flow and its impending rush toward the 317-foot fall.
Smith and his family had hiked up the slick trail to the top of Vernal Fall, and as they stood enjoying the view, a woman nearby began shouting about her son in the water. The boy was bobbing along, swept up in the raging current roughly 30 feet from the waterfall’s plunge downward. Without thinking, Smith raced over the guardrail and toward the young boy, hooking his arm around a nearby rock and reaching out his other arm to grab the child. Smith managed to haul the child out of the river.
Kari Cobb, a Yosemite park ranger said they estimate that many of these rescue attempts are made each summer; however some of them are unsuccessful, perhaps most memorably the deaths of three California hikers in 2011.
“It is very common that rescuers will drown when they are trying to rescue the initial person who went in,” Cobb told the news. “And in a situation with rushing water it’s extremely dangerous for everyone — that’s exactly what happened in 2011, each one was trying to rescue each other.”
The following precautions come directly from the Friends of YOSAR (Yosemite Search and Rescue) website as ways to avoid injury when hiking off-trail near water and waterfalls:
- Don’t trust smooth, wet, sandy, mossy or loose rock for a foothold. Slipping on this stuff in your backyard or on the trail is one thing. Losing your footing next to a cliff or swift water is something else again.
- Don’t get careless next to, or in, streams, e.g., simply filling your water bottle, swimming above dangerous water, boulder hopping, wading across, etc.
- Remember the current is stronger than you think. Cold water saps your strength and reflexes. Rocks are everywhere and hard. You’ll be over a 15-foot drop before you know it. Whitewater is half air/half water-you can neither float in it nor breathe it. Hydraulics, entrapments, and strainers hold you under.
- Cliffs are obviously dangerous (innate fear of heights?). The dangers of whitewater may not be so obvious, and, when standing next to a stream, there is often no height difference to ring the alarm. The risks may have to be learned, hopefully not the hard way.
- Don’t think your skills in one environment (e.g., a strong swimmer in surf) will transfer into a new one (e.g., swift water).