Dozens of hikers visiting Havasupai Falls at the bottom of the Grand Canyon have reported falling violently ill with a mysterious sickness.
In some cases, visitors were too sick to hike back out of the canyon, and needed to be carried out via helicopter.
Maylin Griffiths, who visited the falls in Arizona to celebrate her 40th birthday, told AZ Family that her trip quickly turned into a nightmare after she suddenly fell very ill.
"We [left] early morning on the 6th and then set up camp. We had a wonderful campsite," Griffiths said. "I was throwing up, just a lot of GI issues and then it just progressively got worse and worse."
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Another friend in her group also got severely ill, and the group ended up hiking back several miles to a village in the canyon to get medical attention.
"He discovered our temperatures were really high. Mine was 104 and my friend was 105. We were violently ill. They were able to admit us to the clinic there because they considered it life threatening," Griffiths told the outlet.
Dozens have taken to social media recently with similar experiences, including Mary Blair, who recently spoke to Fox 10 about the nightmare.
She and eleven others set out on a forty-mile hike to the falls, planned over four days. The trip took a turn on the final night of their trip when her son suddenly developed norovirus-like symptoms.
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"He was throwing up and having diarrhea all night long. I got him in the river. We were in there at midnight, 1 o'clock, just to lower his body temperature," Blair told the outlet.
Unbeknownst to them, others in the group were also sick. At 2 a.m., the groups started a two-mile hike out to a helicopter pad to get the sick to safety and medical attention.
"This kid is a four-star athlete. He is the strongest out of all of us. He was using hiking poles, and he could barely walk," Blair said of her son.
"On the way up, all of us were passing people who are throwing up and that's when I was like, what the heck is going on?" Blair told Fox 10. "There’s probably 60–70 people down the line. There are multiple people throwing up."
When they got home, the Blair family saw that over 300 people had posted about similar experiences on Facebook, with symptoms of vomiting and diarrhea.
It's unclear what led to the mass illness, but Blair and her family - who are experienced hikers - told Fox 10 that nearly 400 people were camping in close quarters. Sanitary bathrooms were difficult to find, she said.
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Havasupai Falls is located on the Havasupai Indian Reservation in Coconino County. In a Facebook post, the Havasupai Tribe Tourism Office wrote that the public water sources on the reservation are tested regularly, and were last determined to be safe for human consumption by the Havasupai Water Department on June 6. The next water test of the Fern Spring is scheduled for two weeks from June 11.
"There is an excessive heat warning at this time," the tourism authority wrote. "The Havasupai Tribe reminds all tourists to properly hydrate before, during and after your visit to Havasupai. Please consider supplementing your water intake with electrolytes." "Lastly, it is critically important that all tourists take our their trash, camping supplies and personal items," the post continued.
"Properly dispose of hygiene items. The trash bins in the composting toilets are not for your personal campsite trash... The cost to remove tourist trash and gear by helicopter is substantial."