Adam Spencer, The Triplicate

The Smith River houses California's healthiest population of coastal cutthroat trout, and this weekend the public is invited to take a dive in the crystal-clear river as part of an annual survey used to track the trout's abundance.

The Smith River Alliance invites all wild fish enthusiasts, swimmers and river folk to throw on a snorkel and a wetsuit and participate in the annual Smith River Fish Count this Saturday, where citizen-scientists collect data used by state and federal fishery managers.

"Participating snorkelers will experience wild fish in their native habitat and also enjoy the unsurpassed beauty of the Smith River while floating among the canyon walls and searching within the clear water," says an event flier.

For first-time fish counters, an entry-level river snorkeling and fish identification workshop will be held at Rock Creek Ranch on the South Fork Smith River from 1 to 5 p.m. Friday.The training is required for all first-time participants that want to collect data on Saturday, and veteran fish counters are encouraged to attend to help the workshop or hone their skills.

Registration begins at 8 a.m. Saturday at Rock Creek Ranch. Teams will be assigned stretches of river around 9 a.m., go out and collect data and return to the ranch at 5 p.m. for a barbecue potluck.

Participants are asked to bring their mask, snorkel and wetsuit, although there is a limited amount of gear available for loan at the ranch.Gear can also be rented from South Beach Outfitters in Crescent City and Pacific Outfitters in Arcata and Eureka, which has offered a group discount on gear for Smith River Fish Count divers. Let them know you are with the Smith River Alliance.

Divers should bring their own high-energy snacks, lunch, water bottle, and sunscreen. Camping space is available at Rock Creek Ranch (8 miles up South Fork Road) from Aug. 8andndash;10.

Divers are asked to RSVP to Rachel McCain