California
Toxic algae in Mono County lakes
27 lakes and waterways in Mono County have harmful algal bloom reports in California's official data. The most recent entry is for Crowley Lake: There are no bloom reports for Crowley Lake in the last 30 days of California's data. The most recent was a bloom report on 27 May 2026 at Crowley lake columns. Crowley Lake, Bridgeport Reservoir and Lake Crowley and 4 more have had blooms in three or more years.
Lakes with bloom history
Newest report first. Each lake has its own page with the full history and what the results mean.
- Crowley Lake Bloom reported
- East Walker River Caution
- West Walker River Awareness sign
- Deadman Creek Awareness sign
- Bridgeport Reservoir Caution
- Virginia Creek Bloom reported
- Lake Crowley Bloom reported
- Gull Lake Bloom reported
- Topaz Lake Bloom reported
- Grant Lake Bloom reported
- June Lake Bloom reported
- Silver Lake Bloom reported
- Lake Mary Bloom reported
Other waterbodies with a report
These have one or two reports in a single year, which isn't enough history for a page of their own yet.
- Adobe Creek 2023
- Barney Lake 2022
- Cottonwood Creek 2025
- Crystal Lake 2021
- Hummingbird Lake 2021
- Koenig Lake Creek 2023
- Lost Lake 2025
- Marble Creek 2024
- Mono Lake 2017
- Odell Lake 2021
- Poore Creek 2022
- Rock Creek 2021
- Ruby Lake 2021
- Sardine Creek 2021
Source: California State Water Resources Control Board, official data, checked 24 October 2026. For today's conditions see the California HABs Portal map. No report doesn't mean a lake is safe: most water is only tested occasionally.