07/27/2026
WATER QUALITY UPDATE FROM WYOMING DEQ---
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
7/24/26, 9:16 AM State of Wyoming Mail - Wyoming DEQ Encourages Safe Water Recreation on Lake DeSmet Following Bloom Advisory
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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.
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