Updated November 4, 2022
Zion National Park continues to monitor monthly for the presence of harmful cyanobacteria and cyanotoxins. Zion staff take a “multiple lines of evidence” approach when using data to issue recreational advisories. Monitoring efforts have detected harmful cyanotoxins in North Creek which is elevated to a Danger Advisory. 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. During Warning and Health Watch advisories, recreators should avoid primary contact recreation such as swimming or submerging the head. During Danger advisories, recreators should consider avoiding all direct contact with the water. Do not drink stream water anywhere in the park. Carry in water or filter and disinfect directly from a spring source.
Need to know about cyanobacteria
Children are especially vulnerable to cyanotoxins, so be mindful of where they go if you are near a body of water like the Virgin River.
Learn more about toxic cyanobacteria from: