Dozens of hikers struck down by severe vomiting bug after camping at popular waterfall hike near Grand Canyon

Havasu Falls
Health officials are investigating the claims that a Norovirus-like illness is spreading at the site (Image credit: Getty Images)

Dozens of hikers have been struck down by a severe vomiting bug after camping at a popular waterfall near Grand Canyon National Park over the weekend.

According to a report by the Associated Press, the hikers had been camping on the Havasupai Indian Reservation in Arizona which is known for its incredible turquoise blue Havasu Falls reached via a 10-mile trail.

In the article, a 32-year-old veterinarian named Madelyn Melchiors from Kingman Arizona says she experienced vomiting on Monday and a fever lasting several days. Melchiors says she drank from a spring that is listed as potable and used a water filter when drinking from other sources, however her filter is only designed to remove bacteria and parasites, not viruses.

Melchiors was able to hike out to her car despite the excessive heat in the region, and used a mule to transport her backpack.

 “I slept 16 hours and drank a bunch of electrolytes. I’m still not normal, but I will be OK. I’m grateful for that," she says of the days following her ordeal.

how to store your water filter over winter: man filtering water by mountain lake

Not all water purifiers filter out viruses (Image credit: Getty Images)

The federal Indian Health Service says it is providing medical attention to anyone who becomes ill. 

“Our priority is the health and well-being of the Havasupai residents and visitors, and we are working closely with local health authorities and other partners to manage this situation effectively,” the service says in a statement.

Meanwhile, environmental health officers have been dispatched to Havasupai to investigate the source of the outbreak.

Norovirus can spread easily at campsites – last September, we reported that a cabin on the Pacific Crest Trail had been identified as the source of an outbreak affecting dozens of hikers.

To avoid gastrointestinal illness on the trail, it's important to wash your hands with soap, boil your water before you use it, practice food safety and make sure you have a water filter that removes viruses, or use water purification tablets. Learn more in our article on avoiding tummy troubles in the backcountry.

Julia Clarke

Julia Clarke is a staff writer for and the author of the book Restorative Yoga for Beginners. She loves to explore mountains on foot, bike, skis and belay and then recover on the the yoga mat. Julia graduated with a degree in journalism in 2004 and spent eight years working as a radio presenter in Kansas City, Vermont, Boston and New York City before discovering the joys of the Rocky Mountains. She then detoured west to Colorado and enjoyed 11 years teaching yoga in Vail before returning to her hometown of Glasgow, Scotland in 2020 to focus on family and writing.