Naturalist James Frank is accustomed to seeing animals, but when he witnessed a video of one of the first salmon seen in Marsh Creek in 54 years, it filled him with excitement.

“The video is really impressive,” said Frank, a supervising naturalist for the East Bay Regional Park District. “It’s really cool to see actual salmon swimming in any urban area, but this is especially cool because it’s such a small stream.”

Although only two salmon have been seen in the creek since November, the sightings serve as proof that a fish ladder opened in 2010 is allowing the salmon to reach parts of the lake they haven’t ventured into in 50 years.

“It validates what we do,” said Diane Burgis, executive director of Friends of Marsh Creek Watershed, which worked with about a dozen other organizations to help complete the project about three-quarters of a mile from Homecoming Way in Brentwood. “Sometimes people are not sure that something will work. People work so hard on the concept of an idea, and when it is realized, there’s a real sense of satisfaction. It also energizes you to keep going and want to do more.”

Until the ladder was opened, salmon were stuck on one side of a giant cement drop structure, which was needed to protect the banks from large amounts of water.

Since salmon can jump only as high as they can dive, they couldn’t go any farther. So a notched hallway was built along the drop structure so that flashboards could be installed that create a series of pools that flow into one another. The salmon then jump from pool to pool to bypass the drop structure, and get into upper Marsh Creek, an ideal gravelly habitat in which the fish can lay their eggs.

“Up until the fish ladder was built, we could stand at the stop structure and basically count them right there,” Burgis said. “Now they have another seven miles of creek, and go up to parts of Sand Creek and Deer Creek as well.”

Burgis said the few salmon sightings are a sign of things to come.

Salmon are born in fresh water before entering the ocean for three to five years. Near the end of their lives, they return to their birthplace, where females lay between 1,000 and 5,000 eggs before dying.

“If only three or four of those fish were to survive after hatching, and they were able to come back, then every year that would keep multiplying the population that would come back to Marsh Creek,” Burgis said.

One of the fish sighted appeared to be returning to lay its eggs, Burgis said, while the other appeared to be young. “It really is exciting,” said Tammy Mueller, park supervisor for the East Bay Regional Park District. “You don’t see fish in there every day.”

According to Frank, it’s possible that if conditions are right, the number of salmon will grow in future years during late fall and early winter. “Hopefully with any luck, the number will increase,” Frank said, citing the need for adequate food, water levels and a clean environment.

The slow return of salmon to the creek is symbolic of the gradual effort of the Friends of Marsh Creek Watershed when they first started the project in 2000. The small organization, whose mission is to protect, conserve and restore Marsh Creek, worked with about a dozen organizations, including the Contra Costa Flood Control District and the Natural Heritage Institute, to take the fish ladder from dream to reality.

“It’s a symbol of dozens of organizations and agencies getting together to make something happen,” Burgis said. “For the longest time, it was like: ‘let’s get this fish ladder built’; then it was: ‘let’s get this fish ladder functioning.’ It took a while to adjust the flashboards, make sure it’s maintained properly and make some adjustments.”

Although the fish ladder has earned Friends of Marsh Creek Watershed attention on the state and regional level, the organization is already working on several other projects to improve the habitat within the creek, the water quality and create a citizen monitoring group to track the number of salmon in Marsh Creek.

All work aside, the presence of fish in the creek is causing quite a stir among locals.

“I haven’t seen any fish, but that is freaking awesome,” said James Grey as he watched the video near the Marsh Creek Trail.

Friends of Marsh Creek Watershed is always seeking members. For more information, visit www.fomcw.org.