A report of numerous people being exposed to an unknown poisonous gas and feeling ill led first responders to Vallecito Creek Campground in Colorado’s San Juan National Forest.

The fire district arrived at the scene to find seventeen individuals from four campsites feeling sick. Eight of them exhibited symptoms such as wheezing, nausea, and throat and nose irritation. None of the affected individuals reported eye irritation, which is typically associated with exposure to pepper spray or bear repellent.

Courtesy of Upper Pine River Fire Protection District

Gas monitors were used to test the air quality in and around the affected campsites. No hazardous gases or substances were detected. Chemical bathrooms were also inspected for potential sulfur or methane gas discharge. Those results too were negative.

Fortunately, no individuals required hospitalization, and the situation is being closely examined to determine the cause of the reported illnesses.

The investigation has been taken over by the La Plata County Sheriff’s Office.