Despite the late rains, salmon have been making their way up Lagunitas Creek in their yearly return to their spawning grounds.

Fish monitors such as Greg Andrew of the Marin Municipal Water District said they have already observed several salmon species, including the return of pink salmon for the third year in a row.

“Prior to that, we hadn’t seen them in 30 years,” Andrew said.

Chinook and coho salmon, which are listed, respectively, as threatened and endangered, also have been observed beginning to make their way to the spawning grounds in Lagunitas Creek and eventually other tributaries such as San Geronimo Creek and Olema Creek when the flows are high enough.

While later than usual, this week’s rainfall signaled the salmon to push farther up the creek. As a result, this holiday weekend will be a good time to catch a view of the fish at popular viewing spots such as the Inkwells, the Leo T. Cronin fish viewing area and Samuel P. Taylor State Park.

“We’re really excited for the salmon to return,” said Todd Steiner, executive director of the Olema-based Salmon Protection and Watershed Network, or SPAWN. “It’s one of the incredible spectacles of nature that we get here in Marin that we get to see wild coho salmon spawning. It’s one of the few places left in California where the wild salmon are still doing their thing.”

This year’s run of endangered coho salmon is not expected to match last year’s, which was the highest number recorded in 12 years. But this year’s run and later ones will have the advantage of several habitat restoration projects along Lagunitas and San Geronimo creeks as well as Redwood Creek farther south.

Even with last year’s high count of 369 salmon egg nests, known as redds, and 738 adults, the number is still far short of the recovery target of 1,600 adults needed to bring coho salmon out of its endangered status. There are encouraging signs, as researchers have found that a large portion of the redds that were laid and young coho that were in the water survived the heavy winter flows last year.

Researchers’ forecast of a smaller run stems from a lower number of surviving smolts from a few years ago. Coho salmon spend about a year and a half in freshwater and a year and a half in the ocean before returning to freshwater to spawn and die.

“But the black box is we actually won’t know until we get there,” Steiner said.

When the Marin Municipal Water District surveyed Lagunitas Creek this week, researchers found 10 redd and four adult pink salmon; 13 redd and 41 adult chinook salmon; one redd and one adult chum salmon; and three redd and eight adult coho salmon.

Many of these fish were able to move up earlier this month because of the water district’s state-mandated water releases from Kent Lake, which ramped the water flow to 35 cubic feet per second. These flow increases will occur again on or before Dec. 1 and Jan. 1, when the bulk of coho salmon are moving up the creek and its tributaries and then again around Feb. 1.

“We are excited to conduct surveys next week, after yesterday’s rain and the rain expected this weekend,” Andrew said Wednesday.

Tuesday’s downpour wasn’t likely enough to break the sand bar at Muir Beach to allow fish to begin moving into the 9-square-mile Redwood Creek watershed, according to National Park Service fishery biologist Michael Reichmuth.

“But there is more rain on the way and I think by next week adult coho should have access to Redwood Creek,” he said.

The National Park Service has been working on several projects through the year to improve habitat on Redwood Creek for the salmon, with the park recently overhauling a half-mile stretch of the creek in Muir Woods National Monument.

“The recent restoration project in Muir Woods should not change the spawning activity in this section of the creek but it will help the fish after spawning,” Reichmuth said. “The project was designed to decrease stream velocities during storm events, which should reduce the amount of redd scour during large storm events.”

Other projects by SPAWN, the Marin Resource Conservation District and MMWD this year have similarly worked to improve the habitat for young salmon to rear during their freshwater stay.

“We want the greatest number of small smolts that we can see the creek produce,” Andrew said.