East Fork Russian River: toxic algae advisories
East Fork Russian River, Mendocino County. See all Mendocino County waters.
What the state's records say
Algal mat alert sign, last posted Sep 25, 2026. No all-clear recorded.
2 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: The state recorded an advisory of a type outside the Caution, Warning and Danger levels. Read the sign posted at the water.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at East Fork Russian River
The state has an advisory on file for East Fork Russian River (Algal mat alert sign), last posted Sep 25, 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 |
|---|---|
| Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign, last posted Sep 25, 2026. No all-clear recorded. |
| above Lake Mendocino | Visual observation, last posted Apr 9, 2025. No all-clear recorded. |
Advisory history
Every advisory record the state has published for East Fork Russian 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 |
|---|---|---|---|
| Sep 25, 2026 | Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign | Advisory based on visual and toxins |
| Sep 10, 2026 | Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign | Advisory based on visual and toxins |
| Aug 18, 2026 | Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign | Advisory based on visual and toxins |
| Aug 11, 2026 | Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign | Bottom/benthic bloom observed; Visual monitoring only-present bloom |
| Aug 20, 2025 | Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign | Advisory based on visual and toxins; Alert-detached mats observed; Bottom/benthic bloom observed |
| Aug 13, 2025 | Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign | Alert-detached mats observed; Bottom/benthic bloom observed; Visual monitoring only-present bloom |
| Apr 9, 2025 | above Lake Mendocino | Visual observation | Under investigation |
| Apr 9, 2025 | above Lake Mendocino | Visual observation | Under investigation |
| Nov 26, 2024 | Access near Elledge Ranch Rd (114EF3696) | None | De-posting advisory. |
| Aug 20, 2024 | Access near Elledge Ranch Rd (114EF3696) | Algal mat alert sign | Advisory based on visual and toxins; Bottom/benthic bloom observed |
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.