Trinity River South Fork: toxic algae advisories
Trinity River South Fork, Trinity County. See all Trinity County waters.
What the state's records say
The state's latest record, from Aug 13, 2025, recommends no advisory.
That reflects what the state knew on that date. It is not a finding that the water is safe now: blooms can return within days, and many are never reported.
Before you go, check the state's official algae page and any signs posted at the water.
Dogs at Trinity River South Fork
The state's latest record, from Aug 13, 2025, recommends no advisory. For Trinity River South Fork, that is not the same as an all-clear for today. Look at the water before your dog goes in: keep it out of green, blue-green or scummy water and away from mats on the shore.
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 |
|---|---|
| ~6.5mi above Rasbery Gulch (106PS0124) | The state's latest record, from Aug 13, 2025, recommends no advisory. |
Advisory history
Every advisory record the state has published for Trinity River South Fork, 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 |
|---|---|---|---|
| Aug 13, 2025 | ~6.5mi above Rasbery Gulch (106PS0124) | None | Updates from routine monitoring program-organization |
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.