South Fork Eel River: toxic algae advisories
South Fork Eel River, Mendocino County. See all Mendocino County waters.
What the state's records say
Caution advisory, last posted Oct 9, 2026. No all-clear recorded.
3 reported spots here have an advisory with no all-clear recorded.
Reporting is voluntary, so the state may not have recorded an end even if conditions changed. Check posted signs and the official map.
What this level asks: Algae that can make toxins may be present. Keep people, children and pets away from algae and scum, and do not let pets drink the water.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at South Fork Eel River
The state has an advisory on file for South Fork Eel River (Caution advisory), last posted Oct 9, 2026, and no all-clear recorded. Keep your dog out of the water and away from scum on the shore until the state records an end.
Reported spots
The state records each report at a spot, such as a beach or a boat ramp. Each spot's latest deciding record:
| Spot | Status |
|---|---|
| Standish-Hickey | Algal mat alert sign, last posted Oct 9, 2026. No all-clear recorded. |
| Redwood River Campground | Algal mat alert sign, last posted Sep 19, 2025. No all-clear recorded. |
| Standish-Hickey State Recreation Area | The state's latest record, from Nov 21, 2022, recommends no advisory. |
| Cooks Valley | The state's latest record, from Nov 21, 2022, recommends no advisory. |
| South Fork Eel River at Cooks Valley | Caution advisory, last posted Oct 19, 2020. No all-clear recorded. |
Advisory history
Every advisory record the state has published for South Fork Eel River, newest first. "None" is the state's record that no advisory was recommended on that date. "NA" records do not change a status.
| Date | Spot | State's level | Notes |
|---|---|---|---|
| Oct 9, 2026 | Standish-Hickey | Algal mat alert sign | Visual monitoring only-present bloom |
| Sep 24, 2026 | Standish-Hickey | None | Visual monitoring only-present bloom |
| Sep 19, 2025 | Redwood River Campground | Algal mat alert sign | Suspected illness reported; Under investigation |
| Sep 19, 2025 | Redwood River Campground | Algal mat alert sign | Suspected illness reported; Under investigation |
| Nov 26, 2024 | Standish-Hickey | None | De-posting advisory. |
| Aug 20, 2024 | Standish-Hickey | Algal mat alert sign | Bottom/benthic bloom observed |
| Dec 31, 2023 | Standish-Hickey | None | End date recorded: Dec 31, 2023. De-posting advisory. |
| Nov 3, 2023 | Standish-Hickey | Algal mat alert sign | Advisory based on visual and toxins; Alert-high concentration toxins; Bottom/benthic bloom observed |
| Oct 30, 2023 | Standish-Hickey | Algal mat alert sign | Advisory based on visual and toxins; Alert-high concentration toxins; Bottom/benthic bloom observed |
| Sep 8, 2023 | Standish-Hickey | Algal mat alert sign | Advisory based on visual and toxins; Alert-high concentration toxins; Bottom/benthic bloom observed; Updates from routine monitoring program-organization |
| Aug 29, 2023 | Standish-Hickey | Algal mat alert sign | Advisory based on visual and toxins; Alert-high concentration toxins; Bottom/benthic bloom observed; Updates from routine monitoring program-organization |
| Nov 21, 2022 | Standish-Hickey State Recreation Area | None | End date recorded: Nov 21, 2022. De-posting advisory. |
| Nov 21, 2022 | Cooks Valley | None | End date recorded: Nov 21, 2022. De-posting advisory. |
| Nov 21, 2022 | Standish-Hickey State Recreation Area | None | De-posting advisory. |
| Nov 21, 2022 | Cooks Valley | None | De-posting advisory. |
| Nov 14, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Nov 14, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Nov 8, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Nov 8, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Nov 1, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Nov 1, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Oct 24, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Oct 24, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Oct 18, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Oct 18, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Oct 5, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Oct 5, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Sep 28, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Sep 28, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Sep 23, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Sep 23, 2022 | Cooks Valley | Algal mat alert sign | Advisory based on visual and toxins; Updates from routine monitoring program-organization |
| Sep 21, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Sep 21, 2022 | Cooks Valley | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Sep 21, 2022 | Cooks Valley | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Sep 15, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Sep 15, 2022 | Cooks Valley | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Sep 15, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Aug 29, 2022 | Cooks Valley | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Aug 29, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | Updates from routine monitoring program-organization; visual monitoring based advisory |
| Jul 27, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | visual monitoring based advisory |
| Jul 27, 2022 | Cooks Valley | Algal mat alert sign | Updates from routine monitoring program-organization |
| Jul 13, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | visual monitoring based advisory |
| Jul 13, 2022 | Cooks Valley | Algal mat alert sign | Updates from routine monitoring program-organization |
| Jul 6, 2022 | Standish-Hickey State Recreation Area | Algal mat alert sign | visual monitoring based advisory |
| Oct 19, 2020 | South Fork Eel River at Cooks Valley | Caution | Advisory based on visual and toxins |
Source
Advisory data: California State Water Resources Control Board, Freshwater Harmful Algal Bloom Program, via data.ca.gov (public domain). Advisories are recommendations; reporting is voluntary and incomplete. The state's data. An advisory ends only when the state records a later "None" (no advisory recommended) at the same spot, or an end date. A blank end date is unknown.