Recreational Health Use Advisories lifted at Thief Valley, Prineville Reservoirs

By on Wednesday, December 24th, 2025 in More Top Stories Northeastern Oregon News

PORTLAND — The Oregon Health Authority (OHA) has lifted recreational use health advisories for two reservoirs in central and eastern Oregon.

OHA’s water monitoring has shown the level of cyanotoxins in Thief Valley Reservoir in Baker and Union Counties, and Prineville Reservoir in Crook County are below recreational guideline values for people.

Levels are below safety values for dogs at Prineville but still above levels at Thief Valley, which means pets should still be kept away from affected areas at Thief Valley.

OHA still reminds visitors to be alert to signs of cyanobacteria bloom, noting that only a fraction of water bodies in the state are monitored for blooms and toxins.

People, and especially small children and pets, should avoid areas where the water is foamy, scummy, thick like paint, pea-green or blue-green, or if thick brownish-red mats are visible or bright green clumps are suspended in the water. If those signs are seen people should avoid activities that can cause them to swallow water or inhale droplets, such as swimming or high-speed water activities, and keep pets out of the area.

**Stock image**