The National Park Service is investigating reports of a “mystery illness” among people who recently rafted the Colorado River through the Grand Canyon, after several boaters began describing similar lingering symptoms following trips through the canyon.
In a 12 News video report, journalist William Pitts spoke with Matthew Wappett, a Utah man who said he rafted the river weeks ago and has been sick ever since. Wappett described a rough and confusing recovery that began with an infected knee and turned into weeks of muscle aches, joint pain, and flu-like symptoms that doctors have not yet clearly identified.
“Oh, I’m horrible,” Wappett told Pitts, explaining that the exhaustion has felt far out of proportion to anything he has done since the trip.
“I try to explain it to people,” he said. “It feels like I did a hard workout every day, even though I’ve done nothing except for sit on my butt.”
The report comes as Grand Canyon officials confirm that the National Park Service is aware of illness reports tied to rafters and is working with public health partners to investigate what may be happening.
A River Trip Followed By Weeks Of Symptoms
Pitts reported that Wappett had rafted down the Colorado River at the bottom of the Grand Canyon weeks before the interview.
The illness did not begin, at least in Wappett’s account, as a vague complaint. It started with a skinned knee that he did not initially consider serious.
Wappett told 12 News that the knee later became swollen, red, and painful enough that he needed IV antibiotics, followed by two different oral antibiotics, before the infection finally improved.
“My whole knee just swelled up,” Wappett said. “Then ended up on IV antibiotics and a full course of two different oral antibiotics to finally kill it.”
But even after the infection was treated, Wappett said the rest of his symptoms did not go away. Pitts reported that he continued dealing with muscle and joint aches and flu-like symptoms that have lingered for weeks.
That is the part that makes the situation concerning. A cut or scrape during a rafting trip is not unusual, especially in rough terrain, wet conditions, and remote travel, but a cluster of people describing similar ongoing symptoms raises a different kind of question.
Other Rafters Began Comparing Notes
According to Pitts’ report, Wappett posted about his illness in a Grand Canyon rafters’ Facebook group, where he found other people describing similar problems after time on the river.
One man reportedly wrote that several people in his rafting group had experienced the same kind of symptoms, including severe pain, and that doctors were stumped.
“Not how I intended to go viral,” Wappett said, “but I guess if it gets the word out that there’s something going on down there.”
That comment captures the strange position patients can find themselves in when an illness is not yet identified. They may not know whether they are dealing with a rare infection, an environmental exposure, an unrelated coincidence, or something else entirely, but they also know that staying quiet may keep other cases from being recognized.
The Grand Canyon is remote, and river trips are often spread across separate groups, guides, schedules, and campsites. That can make it harder to spot a pattern quickly unless people begin comparing symptoms after the fact.
In this case, social media appears to have helped connect rafters who may otherwise have thought their illness was isolated.
National Park Service Confirms Investigation
Pitts reported that Grand Canyon officials confirmed Monday that the National Park Service is aware of the reports and investigating them with public health partners.
In the report, the park said the National Park Service Office of Public Health is leading the investigation in coordination with appropriate public health partners.
The agency did not provide a diagnosis or say how widespread the illness may be, noting that the investigation remains ongoing.
“At this time, the investigation is ongoing, and we are not able to comment on the extent of the illnesses, potential diagnoses, or other details while the investigation is underway,” the National Park Service said in the statement cited in the 12 News report.
That caution is understandable. Public health investigations often take time because symptoms that look similar at first can come from many different causes, including infections, water exposure, food-related illness, insect bites, wounds, heat stress, or conditions unrelated to the trip.
Still, the fact that the National Park Service confirmed it is looking into the reports gives the situation a level of seriousness beyond ordinary post-trip illness.
Disease Trackers Are Watching The Reports
Pitts also spoke with Dr. Britta Lassmann, co-founder of Beacon, a crowdsourcing infectious disease surveillance platform at Boston University.
Lassmann said Beacon is tracking the Grand Canyon reports and looking for more information from people who may have been affected.
“It looks like that there are several cases in different groups,” Lassmann said in the report, adding that this makes it feel like there “might be more behind it.”
She also said most disease reports eventually turn out to be something identifiable, but it can take time to determine what that is.
That point is important because the phrase “mystery illness” can sound alarming, but it often reflects an early stage of investigation rather than something unknowable. Doctors and public health officials may need lab results, patient histories, timelines, locations, and exposure details before they can connect the dots.
For people who were recently on the river, though, the uncertainty can still be deeply unsettling. Knowing that others feel sick may validate their concerns, but it does not immediately answer what caused the symptoms or what treatment will help.
A Remote Setting Complicates The Picture
The Grand Canyon is one of the most famous outdoor destinations in the country, but it is also a harsh and isolated environment.
Rafters on the Colorado River may spend days or weeks far from easy medical care, moving between camps, side hikes, rapids, and changing weather conditions. Cuts, scrapes, heat exposure, dehydration, stomach illness, and sore muscles can all be part of demanding backcountry travel.
That makes an investigation more complicated because not every symptom after a river trip will necessarily have the same cause. Some people may get sick from one source, while others may be dealing with unrelated problems that appear similar at first.
At the same time, the repeated descriptions of lingering pain, flu-like symptoms, and infections are exactly the kind of pattern public health officials have to take seriously.
The responsible approach is not panic, but documentation. People who recently rafted the river and developed unusual symptoms should seek medical care, note when symptoms began, document wounds or exposures, and tell providers about the Grand Canyon trip.
Wappett Is Still Waiting For Answers
Pitts reported that Wappett is waiting for more test results and trying to rest while doctors continue looking for an explanation.
“I’m hoping to get some results back today or tomorrow,” Wappett said. “And, you know, I just take it day by day.”
That kind of waiting can be one of the hardest parts of an unexplained illness. Treatment may address one symptom, such as the infected knee, while the broader fatigue and pain remain unresolved.
Wappett said the original knee infection improved after antibiotics, but the remaining symptoms have stayed with him long enough that the rafting trip is no longer just a memory of an outdoor adventure. It has become the starting point for weeks of medical uncertainty.
Pitts’ report did not identify a confirmed cause, and the National Park Service has not announced one. For now, the case remains under investigation.
What The Public Knows So Far
The known facts are limited but significant.
Several people who rafted the Colorado River in the Grand Canyon have reported illness. Wappett said he became sick after his trip and developed an infected knee followed by lasting flu-like symptoms, muscle aches, and joint pain. Other rafters have reportedly described similar symptoms in online groups.
The National Park Service is aware of the reports and is investigating with public health partners, while Beacon is also tracking the situation and seeking more information.
What remains unknown is the exact cause, how many people may be affected, whether the cases share a single source, and whether there is an ongoing risk to other river users.
Until those answers come, the best response is careful attention rather than speculation. The Grand Canyon draws people from across the country because it offers a rare and powerful wilderness experience, but remote trips also require quick reporting when something unusual happens afterward.
For now, the mystery remains unsolved, and Wappett is still waiting for the same thing public health officials are trying to provide: a clear answer to what made him, and possibly others, so sick after time on the river.
Raised in a small Arizona town, Kevin grew up surrounded by rugged desert landscapes and a family of hunters. His background in competitive shooting and firearms training has made him an authority on self-defense and gun safety. A certified firearms instructor, Kevin teaches others how to properly handle and maintain their weapons, whether for hunting, home defense, or survival situations. His writing focuses on responsible gun ownership, marksmanship, and the role of firearms in personal preparedness.
