Advisories are issued by the Wyoming Department of Health (WDH) when cyanobacterial cell densities and/or cyanotoxin concentrations may pose a risk to people engaging in swimming or similar water contact activities in areas where cyanobacterial blooms occur. Because the extent of a harmful cyanobacterial bloom (HCB) may change rapidly or move from one area of a reservoir to another, WDH will issue an advisory for an entire reservoir unless otherwise noted. An advisory for a lake or reservoir should not be interpreted as a lake closure since many areas of the waterbody may not be impacted by a HCB. It is important to note that advisory thresholds may not be appropriate for domestic animals or livestock.

Questions regarding general health risks and symptoms related to cyanobacterial blooms can be referred to Dr. Karl Musgrave, State Environmental Health Epidemiologist, at 307-777-5825.

Advisories Map