Harmful algae mats and bacterial risks continue to impact recreation in the Virgin River watershed, where recent monitoring has confirmed the presence of toxic cyanobacteria at Babylon Road. The Utah Department of Environmental Quality has issued advisories warning that direct contact with or ingestion of these mats can make humans and animals sick.
Algae Presence in Babylon Area
According to the Utah Department of Environmental Quality, monitoring teams observed a small number of harmful algae mats at Babylon Trail and the Babylon Area as of June 29, 2026. While officials noted that wading, fishing, and paddling remain acceptable activities, they urged the public to avoid touching or eating any algae mats.
The department also advised keeping children and animals away from the mats during recreation. These cyanobacteria grow in mats on the riverbed, often attached to rocks or plants, and can appear in various textures and colors including brown, black, tan, or green.
Fatal Risks to Animals
The risk to animals was previously highlighted in mid-May, when the Department of Emvironmental Quality reported that multiple lines of evidence suggested a dog died during the week of May 11–13 after consuming algae mats at Confluence Park.
By June 5, 2026, monitoring updates for the Babylon Road Area also warned that contact with these mats could be lethal for dogs. The National Park Service has been monitoring toxin production in Zion National Park on a monthly basis since July 2020 to track these developments.
Symptoms and Exposure Risks
The toxins produced by cyanobacteria in the Virgin River, including locations such as The Narrows, target the liver and nervous system. Toxins can be absorbed through the eyes, nose, or mouth during swimming, as even invisible pieces of growth may contain enough toxin to cause harm.
Symptoms of exposure include skin rashes, salivation, drowsiness, tingling, numbness, incoherent speech, muscle contractions, vomiting, and diarrhea. The Department of Environmental Quality advises visitors not to drink water from streams or rivers in Zion National Park, noting that there is no known recreational filtration method capable of removing these toxins.
Understanding HUS and E. Coli
In addition to algae-related risks, the Utah Department of Health and Human Services provides information on Hemolytic Uremic Syndrome (HUS), a condition that can damage and inflame small blood vessels in the kidneys.
According to the Utah DHHS, HUS is often caused by infection with certain strains of Escherichia coli (E. coli) bacteria. Common symptoms include several days of diarrhea, which is often bloody. The department notes that the infection can be contracted through contact with infected feces or improper food preparation.
Safety Recommendations
To maintain safety, the Department of Environmental Quality recommends that visitors shower after coming into contact with recreational water and wash hands with clean water before eating. If exposure is suspected, individuals should immediately contact the Utah Poison Control Center at 800-222-1222.
