For 70 years, a concrete barrier sealed off Alameda Creek in California from the bay. The water behind it was widely considered lifeless, with no salmon or steelhead returning to spawn. In the fall of 2025, work crews finally removed that barrier, and within days, two Chinook salmon were observed swimming upstream through water that had been inaccessible to them since before the first moon landing.
The fish were not stocked or guided there by humans. Their sudden arrival surprised biologists and marked a symbolic milestone in a restoration project that has been underway for nearly three decades.
The creek, located in the South Bay area of Fremont, was once the most productive salmon and steelhead stream in the entire San Francisco Estuary. Its watershed spans roughly 700 square miles, making it the largest tributary feeding the estuary. For thousands of years, it carried large runs of Chinook salmon, steelhead, and lamprey between the ocean and inland spawning grounds.
That changed in the mid-20th century. Between 1965 and the mid-1970s, work crews lined the lower 12 miles of Alameda Creek with concrete and reshaped it to control flooding and provide water for the growing suburbs. The project succeeded in moving water quickly and protecting nearby communities from flood damage, but it transformed the living river into a sterile channel with steep gray walls, a flat concrete floor, and shallow water with no places for fish to rest or hide.
The infrastructure did more than degrade habitat. Migrating salmon and steelhead depend on a precise life cycle that requires open passage between the ocean and freshwater spawning grounds. Along Alameda Creek, that passage was broken at 18 separate points. A single barrier is enough to collapse the cycle for an entire run of fish. Along this creek, there were 18.
The last steelhead seen in the upper creek was documented in 1967. After the concrete channels and rubber dams were built, the fish stopped coming altogether. The creek that once produced more salmon than any other stream in the South Bay went silent for a full generation.
That silence was what Jeff Miller encountered in the summer of 1997. He walked the creek from its mouth at the bay up into the hills over two days, passing the concrete channel, the quarry lakes, and finally reaching the free-flowing water above the development. He later said he fell in love with the creek and assumed he could bring steelhead back in a few years. It took 28.
Miller founded a small nonprofit called the Alameda Creek Alliance that same year, the year steelhead were listed as threatened under the Endangered Species Act. Early on, he said, water district officials told him to leave when he raised the idea of making the creek passable for fish. He changed tactics and organized local anglers and residents to rescue fish trapped in shrinking pools below barriers, ensuring television news crews were present to document it. He also asked the public to send brightly colored postcards to the relevant agencies, each carrying a simple message: “I want steelhead back in my creek.”
The postcards, along with lawsuits and scientific studies, gradually shifted the culture of the water agencies. Although their primary missions were water supply and flood control, they began planning and budgeting for fish passage. A multi-agency task force formed, including the San Francisco Public Utilities Commission, the Alameda County Water District, state and federal wildlife agencies, and a growing list of nonprofits.
The barriers came down one by one. Two old dams were removed in Niles Canyon in 2006. The first of the rubber dams in Fremont was removed in 2009. In spring 2022, crews completed a large fish ladder at one of the creek’s biggest flood control structures. By 2023, 17 of the 18 barriers had been addressed. The work was expensive, ultimately costing more than $100 million in state and federal funds and water district budgets. The Alameda County Water District alone contributed roughly $80 million.
For years, survey data showed little sign of recovery. Between 2015 and 2023, biologists conducting catch-and-release surveys in the creek captured a total of 295 young steelhead, an average of about 37 per year. Then in 2024, a single season produced more than 2,500. It was not a modest improvement but a surge that suggested the reopenings were working. About 50 tagged fish from that year were also observed heading toward the bay and the open Pacific.
One barrier remained for years at a PG&E natural gas pipeline crossing near Sunol. The pipeline had been buried beneath the creek and protected by a thick layer of concrete that settled into a vertical drop of about eight feet. For fish, that drop functioned as an impassable cliff.
In the summer of 2022, PG&E contacted the nonprofit California Trout with an unusual proposal. The pipeline needed long-term protection, and the two organizations decided to solve both problems in a single project. They would relocate the pipeline and reopen the creek at the same location. Federal funding from NOAA Fisheries helped cover the work, which came to about $15 million for this final segment. For PG&E, it was the first time the company had partnered with conservation groups on a project of this kind.
In the summer of 2025, crews moved the gas pipeline about 30 meters away from the creek and buried it roughly six meters deep. They removed the concrete wall that had formed the barrier, then reshaped about 1,800 feet of the creek into a gentle slope so water, fish, and gravel could move naturally.
By fall 2025, the last major barrier on the main stem of Alameda Creek was gone. On November 19, 2025, during routine monitoring, biologists spotted two Chinook salmon between 12 and 24 inches long holding in the current just upstream of the former barrier site. They had made their way past the old pipeline crossing, more than 20 miles from the mouth of the creek. Claire Buchanan, who led the steelhead project for California Trout, described the arrival of the fish immediately after construction finished as one of the best feelings, noting that in this field, success usually takes years to measure.
These particular fish were likely hatchery-raised, not members of a hidden wild population. Even so, they perform a real ecological function. When salmon spawn and die, they carry ocean nutrients into the creek, feeding insects and trees and fertilizing the broader food web. The fish also demonstrated the central premise of the restoration effort: remove the barrier and the fish will find the way.
Steelhead, the species the campaign was originally built around, remain harder to track. They often migrate at night and avoid humans. An electronic antenna installed just above the old barrier site recorded no tagged adult steelhead crossing by spring 2026. But the antenna only records fish that carry tags, and untagged fish leave no record at all. In February 2026, water district staff captured video of male and female steelhead using a fish ladder lower on the creek, the first adult steelhead documented moving past the lower barriers in decades.
The restoration is not complete. Calaveras Dam, a major water supply facility, remains in place, meaning fish will never reach the last mile of their historical range in this watershed. Full restoration was never the goal. The goal was to give the fish a chance to survive, and for the first time in 70 years, they have one.
Miller and his partners are now working on improving survival conditions in the lower flood control channel, restoring tidal marsh at the creek’s mouth, and pursuing a pilot project to reintroduce beavers to the watershed.
Miller has said that the first time he finds a wild steelhead spawning in the upper creek, he expects to fall down and cry. After 28 years, the people who know this story would not hold it against him.
