Wyoming DEQ Encourages Safe Water Recreation on Lake DeSmet Following Bloom Advisory
Wyoming Department of Environmental Quality sent this bulletin at 07/24/2026 08:00 AM MDT
Wyoming DEQ Encourages Safe Water Recreation on Lake DeSmet Following Bloom Advisory
CHEYENNE, WYOMING - The Wyoming Department of Environmental Quality (WDEQ), in collaboration with state partners, wants to reassure residents and visitors that Lake DeSmet remains open for swimming, boating, and other recreation activities. Although a Bloom Advisory was recently issued following confirmation of a harmful cyanobacteria bloom (HCB) near the Mikesell-Potts Recreation Area, blooms are typically localized along portions of the shoreline and not widespread throughout the lake.
Bloom Advisories are issued for an entire lake because blooms can move with wind and water currents and may reappear in different locations. Because it is not possible to determine visually whether a bloom is producing toxins—and because toxin production can change over time—people should treat any visible bloom as potentially harmful and avoid contact with the bloom.
Recent water samples collected from the bloom at Lake DeSmet detected no cyanotoxins, and the cyanobacteria species identified in the bloom is not known to produce toxins. WDEQ will continue monitoring Lake DeSmet over the coming weeks to track bloom conditions.
Conditions can vary across a lake, and much of Lake DeSmet currently remains clear and suitable for summer activities. This is often the case for Wyoming lakes under a Bloom Advisory, where localized blooms may be present while most of the waterbody remains suitable for recreation use.
To enjoy the water safely, visitors are encouraged to practice the simple message: "know it and avoid it." Before entering the water, check your immediate surroundings and avoid areas with visible green scums, floating mats, or unusually discolored water. Keep children and pets away from bloom material, avoid swallowing untreated lake water, and rinse off with clean water after recreating.
By staying aware of local conditions and avoiding blooms, residents and visitors can continue to safely enjoy Wyoming's lakes and reservoirs throughout the summer.
For the latest information on Wyoming bloom advisories, visit WyoHCBs.org.
