
River Riffle Newsletter – May
Contents
- Current Conditions: Cold Water Safety & Invasive Golden Mussels
- Program Updates: Upper Conner Creek restoration to resume
- Featured Article: Cattail versus Tule
- Trinity River Watershed Spotlight: Northwestern Pond Turtle
- Upcoming Meetings and Events
- Reading, Listening & Watching
Current Conditions

Cold Water Safety
As air temperatures climb so do visitors to the Trinity River. Please be aware that waters up and down the river corridor are very cold and the river is swift this time of year. When visiting, please take necessary river safety precautions! Check out Recreate Responsibly Water Safety for tips and remember that life jackets are a must this time of year.
The river is always changing! Click here to view the 2025 water year release schedule.

Invasive Mussels
With the recreation season upon us it’s more important than ever to inspect your water craft if travelling between systems. The highly invasive golden mussel pose a significant threat to the health and functionality of, water conveyance systems, infrastructure, native wildlife, water crafts and water quality. Individuals can help by inspecting, cleaning, draining and letting equipment dry so that these invasive mussels don’t cause significant damage and costly restrictions.
Additional information on the golden mussel prevention can be found by visiting California Department of Fish and Wildlife page: California’s Invaders: Golden Mussel
Program Update
Upper Conner Creek Phase II Rehabilitation

Upper Conner Creek – Phase II Civil Construction Update
Construction is set to resume at the Upper Conner Creek Channel Rehabilitation site soon as flows recede from the R2 construction area.
Due to current flows and public safety, project managers have temporarily closed recreational entry to the site. The temporary closure will affect access for river recreationists across the highway from the Junction City Campground. While we had hoped to maintain some level of public access the current launch is on private property, unsafe and inaccessible due to current conditions which led to an unavoidable short-term closure. This will expedite the timeline to a functional river entry point on public lands, likely mid-July. The river is still accessible a few miles upstream of the project at Sky Ranch or Evans Bar or downstream of the project at Bagdad or Pigeon Point.
To stay up to date on public access at this location, please click here.
Featured Article

Cattail versus Tule
Typha latifolia & Schoenoplectus acutus
Explore the intriguing differences between cattail and tule, two wetland cousins. Our riparian and aquatic ecologist, Simone Groves uncovers the characteristics that distinguish these essential wetland plants, their ecological roles, how each species helps support bird populations and maintains healthy wetland ecosystems, alongside their historical significance and uses by indigenous cultures. Join us in unraveling the rich biodiversity and ecological importance of these keystone species in California’s wetlands!
Photo: Cattail found in a wetland area in the Hoopa Valley. [Simone Groves, Hoopa Valley Tribal Fisheries]
Trinity River Watershed Spotlight

Northwestern Pond Turtle
Actinemys marmorata
Hiding in plain sight along the Trinity River, a quiet survivor faces an uncertain future. Meet the northwestern pond turtle: elusive, marbled, and increasingly at risk. Discover how cold-water dam releases, hungry bullfrogs, and smart restoration strategies are shaping the future of this remarkable reptile. Dive into the full story and see what’s being done to protect California’s native freshwater turtle, the northwestern pond turtle.
Photo: A northwestern pond turtle hatches in Humboldt County. [Don Ashton]
Upcoming Meetings and Events
For a full list of events, click to view the TRRP Calendar.

Apr. 16-18, 2-6pm – Big Flat Jamboree
Big Flat, Ca.
The Big Flat Jamboree features boating competitions, live music, raffles, and community events on the Trinity River. We will have a table and tent set up – come visit us and stay to enjoy food, music, competition and celebration of our rafting community!

May 28, 6pm – Science on Tap
Trinity County Brewing Company
This month’s Science on Tap features a presentation from Eli Asarian, Aquatic Ecologist/Hydrologist, who will present: “Northwest California Beavers in Motion: Past, Present, and Future”
Eli has studied river flow, water quality, salmon, and beavers in California and Oregon rivers for over 20 years, emphasizing the Klamath-Trinity Basin. He has assisted with development and implementation of salmon recovery plans throughout California and is president of the Salmonid Restoration Federation.
This event will be our last Science on Tap this season!

May 31, 9am – 2pm Grass Valley Creek Watershed Tour
Trinity County, Ca.
In collaboration with the Trinity County Resource Conservation District we are hosting a guided exploration of restoration efforts and ongoing stewardship on Grass Valley Creek – a tributary to the Trinity River. Join a host of experts from organizations steeped in restoration efforts and learn the rich history of this infamous sediment-bearing creek that contains 17,000 acres underlain by highly erodible decomposed granite. Over the past 100 years, the surrounding watershed has been hit hard by mining, devastating fire, heavy logging, extensive rural road networks, along with decades long efforts to rehabilitate the watershed and restore the anadromous fishery in the Trinity River.
Space is limited! Please RSVP to Duncan McIntosh (dmcintosh@tcrcd.net) at 530-623-6004 x222.

June 17 & 18 – All Day Quarterly TMC Meeting
Arcata, Ca. & virtual via Microsoft Teams
Reading, Listening, Watching
Wet Season’s end for Water Year 2025 | California Water Blog
Apr. 27, 2025 By Christine Parisek

Statewide precipitation this wet season has been unusually average overall (104%), but a bit weird otherwise. The north was unusually wet (and without major floods), but the south was unusually dry – so extremely dry for months that the south had extensive wildfires in January! Continue Reading …
‘Really unusual’: New study shows why salmon vanished in Northern California | SF Gate
Apr. 10, 2025 | By Amanda Bartlett

It also demonstrates the species’ resilience.
Investigate the alarming decline of steelhead trout and coho salmon in California, highlighted by a recent study that revealed the impacts of an exceptionally dry winter on these native fish populations. Researchers Suzanne Rhoades and Cleo Woelfle-Hazard discovered that both species were missing from watersheds, prompting an extensive investigation that underscored their vulnerability to extreme environmental events. Yet, despite these challenges, the resilience of salmon populations is evident as they repopulated affected sites, reinforcing the importance of biodiversity and conservation strategies. Join us to explore the findings of this pivotal research and its implications for the future of salmon and their habitats in a changing climate. Continue Reading …
Golden Mussels – Help Stop the Spread of the Invasive Species | California Department of Water Resources
March 27, 2025
Help stop the spread of the invasive golden mussel by learning about them from the California Department of Water Resources. Click above to watch!
Contact Us
Call Us: 530-623-1800 Email Us: info@trrp.net