A custom in the Oakdale area, local school children get the chance to take a field trip to Knights Ferry and watch a little slice of life.

It’s the annual trip to the Stanislaus River for the return of the salmon, coming back to spawn. The lessons in the outdoor classroom have been hosted over the past couple of weeks, as more than 400 students from Oakdale elementary schools made the trip to the Ferry.

Classes of fourth graders arrived at the Knights Ferry Recreation Area for the roughly two-and-a-half-hour outdoor lesson that follows two days of classroom instruction about salmon.

The program was started more than 20 years ago by teacher Anne Marie Bergen as part of the science and California history curriculum. Five years ago, teacher Krista Smith took it over. Before the field trip, she visits classrooms at Cloverland, Fair Oaks, Magnolia and Sierra View elementary schools to introduce the salmon’s role in the river ecosystem.

Students learn about the fish’s life cycle and the many challenges salmon face between their beginning in the river, their perilous migration through predatory waters to the ocean, and their return a few years later to spawn and then die.

“The fourth-grade science standards taught in the classrooms, which include the study of ecosystems and survival, blends in beautifully with my lessons and the field trip,” said Smith.

Youngsters also are asked to create charts of year-to-year salmon population numbers provided by Oakdale-based FISHBIO. The importance of the proper habitat for spawning adults and young fish is explained. Chillers paid for by the Oakdale Irrigation District, which also sponsors the field trips, allow at least one classroom on each campus to raise salmon eggs.

Smith, with nearly a dozen local volunteers, lead the lessons that also include teachers and parent chaperons along with the students. There are several aspects to the outdoor ed portion.

Some started with a nature walk led by Pam Warner and Larry Podolsky, the students keeping track of various items on a checklist as they walked a path filled with discoveries about plants and animals.

Podolsky asked if students knew what an anadromous fish was; most did (it is a fish, like salmon, that can move between fresh and salt water). Warner described the food chain and the significance of animal droppings (called scat), and helped interpret tracks left by a deer. Nearby, retired Modesto Junior College biologist Richard Anderson had microscopes and plastic bins of water arranged on picnic tables. There, students peered into the lens to see what young salmon eat – tiny animals like scuds, water mites, caddisfly larva and dozens of other tiny organisms all are found in the Stanislaus.

A rope grid placed on the ground shows how salmon use the unique smells in the water to make their way back from the ocean through the Delta and into the same river in which they were hatched.

Students also had the chance to tour the Army Corps of Engineers museum and watch a short video. The museum is filled with exhibits of native animals – from bears, bobcats and coyotes to red-tailed hawks, owls and turkey vultures to the fish that share the river with salmon. A touch table allowed youngsters to feel the fur of a bear, skunk and other creatures. Retired teacher and tour guide Leslie Thompson also explained the region’s gold mining history and its effect on salmon as well as the impact of dam construction over the past 100 years.

But the most popular part of the day often is the tour segment led by rangers from the U.S. Army Corps of Engineers. After a hands-on demonstration that underscores how few young fish survive a danger-filled gauntlet to the ocean, students are led single file to the bridge and a chance to see salmon for themselves.

The fish, some of them more than three feet long, can be seen against the rocky bottom of the river. Females use their tails to create nests, or redds, in the gravel. Once they lay their eggs, a nearby male will fertilize them. Six weeks later, the first young salmon, or fry, will begin the life cycle again.

This year has been a good year for salmon migration. By Nov. 12, FISHBIO had counted more than 7,000 adults at its weir west of Riverbank. That’s already more salmon than returned in 2014.