LAS VEGAS (KLAS) — Zion National Park continues to see toxic algae blooms that pose health dangers, adding a popular area known as “The Narrows” to a list of places that carry a “warning” advisory.

The North Fork of the Virgin River, including The Narrows, was added to the list on Wednesday, Nov. 8. That area joins North Creek (including “The Subway”), which has carried the warning designation since July 31.

Cyanobacteria in the waterways should not be disturbed. An incident in July of 2020 ended in a puppy’s death after it “snapped” at algae growing on rocks in the North Fork. Cyanobacteria can affect people and pets.

The Utah Department of Environmental Quality sets the levels from “health watch” to “warning” to “danger,” depending on the risk. On Wednesday, the North Fork was upgraded to warning with this note:

“Harmful algal mats (benthic cyanobacteria) are present and producing toxins. Avoid touching or disturbing algal mats. Avoid primary contact recreation (swimming and submerging the head) when recreating in this area. Do not drink in-stream water anywhere in the park. If you must filter water, do so directly from a spring source.”

Currently, Zion lists these statuses in the park:

  • Warning: (more severe) North Fork of the Virgin River (The Narrows, Pine Creek, Deep Creek, Kolob Creek, Orderville Canyon, Emerald Pools and all canyoneering routes with an active surface water connection to the North Forth of the Virgin River)
  • Warning: (more severe) North Creek is a tributary of the Virgin River. It includes the Right Fork, Left Fork (The Subway), Grapevine Spring and all canyoneering routes with an active surface water connection to North Creek
  • Health watch: (less severe) A health watch remains in effect for the other two areas monitored for cyanobacteria, the La Verkin Creek (La Verkin Creek, Timber Creek, Hop Valley Creek and all canyoneering routes with an active surface water connection to La Verkin Creek)

On Wednesday, Zion National Park released changes to shuttle schedules and campground availability. Complete information is available on the park’s website.