A harmful cyanobacteria bloom (HCB) recreational use Bloom Advisory has been issued for Ocean Lake (at the Long Point Ramp) in Fremont County, as well as for Deaver Reservoir in Park County, the Wyoming Department of Environmental Quality shared this week.
The Wyoming Department of Health (WDH) works cooperatively with the Wyoming Department of Environmental Quality to issue recreational use advisories when cyanobacteria cell densities or cyanotoxin concentrations pose a risk to people engaging in swimming or similar water contact activities in areas where cyanobacteria blooms occur. HCBs may also pose a health risk to animals. The WDH is working directly with resource management agencies to ensure signs are posted at the reservoir. Additional details regarding advisories and other HCB resources can be found at WyoHCBs.org.
Bloom advisories are issued when a HCB is present and cyanotoxins may be present. Toxin advisories are issued when cyanotoxins exceed recreational thresholds. Waterbodies under an advisory are not closed since HCBs may only be present in certain areas and conditions can change frequently. Bloom advisories will remain in place until blooms have dissipated, and toxin advisories will remain in place until cyanotoxin concentrations are below recreational use thresholds, as identified in Wyoming’s HCB Action Plan.
If you encounter a potential HCB, the Wyoming Department of Health and the Wyoming Livestock Board recommend the following:
- Avoid contact with water in the vicinity of the bloom, especially in areas where cyanobacteria are dense and form scums.
- Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.
- Rinse fish with clean water and eat only the fillet portion.
- Avoid water spray from the bloom.
- Do not allow pets or livestock to drink water near the bloom, eat bloom material, or lick fur after contact.
- If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.
Questions about health effects and recreational use advisories can be directed to Cori Herzberger, Epidemiologist, Wyoming Department of Health, at cori.herzberger@wyo.gov or (330) 979-0846. Questions regarding cyanobacteria sampling can be directed to Rachel Eyres, Recreational Water Quality Coordinator, Wyoming Department of Environmental Quality, at rachel.eyres@wyo.gov or (307) 777-2073.
Current HCB Recreational Use Advisories*Waterbody Name Observation or Sampling Location(s) Advisory Type Date Issued Alcova Reservoir Black Beach and Kids Beach Bloom 8/12/2026 Beck Lake Dog Park Bloom 7/9/2026 Bighorn Reservoir Horseshoe Bend Beach Bloom 7/9/2026 Big Sandy Reservoir Southeast Shore Bloom 7/17/2026 Boysen Reservoir Fremont Bay Campground Toxin 8/18/2026 Boysen Reservoir Marina Campground Toxin 8/18/2026 Boysen Reservoir Tamarask Campground Toxin 8/18/2026 Boysen Reservoir Tough Creek Campground Toxin 8/18/2026 Boysen Reservoir Tamarask Campground Bloom 7/13/2026 Brooks Lake Outlet Bloom 7/21/2026 Deaver Reservoir Northeast Shore Bloom 8/28/2026 Fontenelle Reservoir West Central Ramp Bloom 8/27/2026 Glendo Reservoir Custer Cove Campground Bloom 7/16/2026 Goshen Hole Reservoir Northwest Campground Bloom 8/12/2026 Grayrocks Reservoir East Central Boat Ramp Bloom 7/2/2026 Guernsey Reservoir Black Canyon Cove Campground Bloom 6/19/2026 Hawk Springs Reservoir Northwest Ramp Toxin 8/11/2026 Hawk Springs Reservoir Northwest Ramp Bloom 8/6/2026 High Savery Reservoir Shore Bloom 7/2/2026 Little Soda Lake Shore Bloom 7/13/2026 McKenzie Lake Dog Park Shore Bloom 7/16/2026 Miller Lake Shore Bloom 7/31/2026 Ocean Lake Long Point Ramp Bloom 8/28/2026 Pathfinder Reservoir Bishops Point Bloom 7/16/2026 Saratoga Lake West Central Beach Bloom 7/28/2026 Sloans Lake South Beach Bloom 8/4/2026 Sodergreen Lake Shore Bloom 8/17/2026 South Worland Pond Shore Bloom 5/26/2026 V Lake Shore Bloom 7/31/2026 Viva Naughton Reservoir Northwest Campground Bloom 8/27/2026 Wheatland Reservoir #1 Northwest Ramp Toxin 8/11/2026 Wheatland Reservoir #1 Southwest Ramp Bloom 7/16/2026 Wheatland Reservoir #3 South Boat Ramp Bloom 8/17/2026 Wind River Below Dam Bloom 8/17/2026 Wind River Lake Shore Bloom 7/30/2026 Woodruff Narrows Reservoir West Shore Bloom 8/12/2026

