Published July 29, 2026 04:11PM
Ten adults and one minor are hospitalized after eating wild mushrooms they foraged outside of Yellowstone National Park in Montana.
On the evening of July 27, emergency personnel responded to a private home in Park County, Montana, which borders the park, where people were suffering from symptoms indicative of poisoning after they collected and ate wild mushrooms.
Jon Ebelt, a spokesperson for the Montana Department of Health and Human Services (DPHHS), told Outside that as of this publication, all of the victims were still in the hospital, seven of whom were in serious condition.
“Based on preliminary information, authorities believe this is an isolated incident, and there is no indication of an ongoing threat or risk to the general public beyond those inherent in mushroom foraging,” Ebelt said. “There is no indication that this incident is tied to any restaurants or grocery establishments.”
Officials are investigating the incident, Ebelt said. The DPHHS did not provide Outside with further details about what type of mushrooms were consumed.
According to the nonprofit educational group, Northwest Mushroomers Association, there are about 7,400 poisonings from ingesting poisonous mushrooms each year in the U.S. and about three deaths. In March, for example, 40 people fell ill, and another four died during a mushroom poisoning outbreak in California.
Montana is home to hundreds of mushroom species, most of which are not considered edible, Cathy Cripps, a mycologist with the group Western Montana Mycology, told Outside.
“While only a few are potentially deadly, there are quite a few that can make you sick or simply don’t taste good,” Cripps said. “Folks should stick to the well-known choice edibles.”
While authorities haven’t disclosed the type of mushroom involved in the recent poisoning, a commonly confused species in Montana and throughout the broader Pacific Northwest, for instance, is the morel mushroom, a highly prized, deeply savory wild fungus known for its honeycomb-like cap. Foragers often confuse morels, which have pits and ridges, with their wrinkly cousin, the false morel. False morels contain a dangerous toxin called gyromitrin, which can cause severe illness or death when consumed.
But even true morels can pose a danger when undercooked, Cripps said.
“They need to be cooked until crispy, as true morels are also poisonous raw,” she said.
In less severe cases, ingesting a poisonous mushroom can have similar effects to food poisoning, including vomiting or diarrhea that a person can quickly recover from. More extreme toxins found in mushrooms can cause neurological symptoms like dizziness, tingling in the arms and legs, hyperactivity, and death, Cripps said.
“The most deadly mushrooms do not cause any symptoms for a few hours, then vomiting might occur, and while the patient seems to be recovering, the cyclopeptide toxins are moving through the bloodstream, destroying liver and kidney cells, which is potentially deadly,” she told Outside.
What to Do in the Event of a Suspected Poisoning
If you are someone you know who is believed to have ingested a poisonous mushroom, the Northwest Mushroom Association says to call 911 immediately.
You can also call the Poison Control Center at 1-800-222-1222.
- Collect and place in a paper or plastic bag all the remaining mushrooms and discarded mushroom trimmings, and make notes of where the mushrooms were collected from.
- Make a note of when the mushrooms were ingested, how much of each type of was consumed, what you thought the mushroom species were, and how the mushrooms were prepared.
- You will need to give the bag of mushrooms and your notes to the emergency responders or the emergency room attending physician.
- If you do not have any mushroom remnants, ask a friend to go back to the place you harvested the mushrooms from and gather samples to give to the emergency room attending physician.
How do you find safe mushrooms? Cripps says to identify the intended edible species using reputable books or websites (not AI) or, better yet, a person experienced in foraging.
“There are no shortcuts,” she said.
Even edible mushrooms can make a person sick if they’re not properly taken care of. When foraging for mushrooms, Cripps says to avoid using a plastic bag and instead opt for a basket or paper bag.
“The mushrooms sweat in plastic and bacterial growth is possible,” she said. “Keep the mushrooms as cool as possible in transit; do not simply put them in the back of your hot car. Put them in a cooler and get them into the fridge as soon as possible (and then in a paper bag or Tupperware container).”
Recommendations now call for cooking all mushrooms well, usually by sautéing them until golden brown, which also brings out the flavor, Cripps added.
“Bottom line: treat mushrooms as you would treat chicken,” she said.
There are several thousand species of mushroom, but only a handful that will kill you. And the toxins found in poisonous mushrooms are some of the deadliest natural poisons on earth. Just seven milligrams—one quarter of a grain of rice—is enough to kill an adult.
If you want to know what it feels like when you eat a deadly mushroom, check out this Outside podcast episode from the archives.
