Zion National Park Warns Visitors After Finding Toxic Bacteria on Two Popular Hikes

by Caitlin Berard
(Photo by lightphoto via Getty Images)

In the summer of 2020, a 6-month-old husky puppy named Keanna was exploring Zion National Park with her adoring owner. Despite the heat and the crowds of July, the pair were having a fantastic time summiting mountains, climbing rocks, and fording rivers. They then chose to traverse The Narrows, the narrowest section of Zion Canyon and one of the most popular hikes in the park.

Aiming to see as much of the spectacular park as possible, Keanna and her owner waded into the Virgin River. The water was threaded with algae, but the two adventurers paid it no mind, continuing on their trek. Tragically, just twenty minutes later, Keanna was dead.

Confused and racked with grief, Keanna’s owner couldn’t believe what they were seeing. She was perfectly healthy moments before, how could this have happened? They had no idea that the culprit lay beneath their feet. The substance coating the river wasn’t algae at all but deadly cyanobacteria.

Though they play important roles in marine environments, cyanobacteria are dangerous to both humans and pets. In adults, cyanotoxin exposure can result in rash, drowsiness, burning, numbness, seizures, and stomach upset. In children and pets, however, it can be lethal.

Late last week, visitors to Zion National Park were horrified to learn that the toxic bacteria had returned. Officials discovered cyanobacteria on not one but two popular trails.

Zion National Park Officials Warn Visitors of Dangerous Cyanobacteria

On Friday, Zion National Park officials warned visitors to exercise caution, as toxic bacteria laced the waters of two of their most popular hiking areas. “Monitoring efforts have detected harmful cyanotoxins in North Creek which is elevated to a Danger Advisory,” they wrote in a statement.

“Toxin-producing cyanobacteria has been detected in the North Fork of the Virgin River which will remain at a Warning Advisory. Toxin-producing cyanobacteria has been observed in La Verkin Creek which will remain a Health Watch.”

Per the statement from Zion National Park officials, hiking in the park is still perfectly safe. However, adventurers should exercise extreme caution near the Virgin River and La Verkin Creek.

Direct contact with water should be avoided entirely, and stream water should not be ingested. Water should always be carried in, except in the case of hikers equipped with filtering/disinfecting gear, who can gather water directly from a spring source.

“When you undertake the Narrows hike, you are committing to wading through water affected by this cyanobacteria,” the park shared on the official ZNP Facebook page after detecting the bacteria in 2020. “There is currently an elevated risk to entering the water. The river is not closed, but we recommend avoiding this risk altogether by simply not entering the water.”

Though the risk is particularly high at the moment, avoiding the water of Zion National Park is a good rule of thumb in general. The current advisory is just one of many from this year alone. ZNP officials issued warnings in October, June, and May as well. The park’s river system has been found to contain six times the level considered dangerous in certain areas.