At least 24 Pacific Crest Trail hikers near Wrightwood, California, have fallen ill in a suspected norovirus outbreak, with seven confirmed cases and one 73-year-old hiker airlifted to a Lancaster hospital.
A water cache in Swarthout Valley is a central focus of the investigation, though a local volunteer said the source could be farther south because norovirus can incubate for about 48 hours.
Trail volunteers have replaced the shared fill station with sealed water bottles, and lodging that typically hosts PCT hikers has temporarily closed to limit further spread.
Norovirus is the leading U.S. cause of vomiting and diarrhea and can spread through contaminated water, food, surfaces, or person-to-person contact—risks heightened for thru-hikers with limited sanitation access.