This particular fallen redwood was a testament to the evolving strategies in salmon restoration. In September 2020, Trout Unlimited’s partners had meticulously selected and strategically placed a redwood into the river to enhance coho-friendliness. This initial log, however, had since been displaced and crushed by a much larger redwood, likely dislodged and carried downstream by the heavy winter rains. The resulting accumulation of debris had inadvertently created an even more "messy" environment than Halligan could have intentionally engineered, a scenario that proved to be highly beneficial. Within moments of Halligan observing the enhanced habitat, a young, silvery coho salmon darted into view within the newly formed pool, a promising sign of the habitat’s effectiveness.

Coho salmon, anadromous fish that journey between freshwater streams and the vast Pacific Ocean, have historically played a vital role in the ecosystems and cultures of the Pacific Coast for millennia. Fred Simmons, an environmental technician for the Cahto Tribe of Laytonville Rancheria, vividly recalled his childhood experiences with abundant coho runs. He described them as being "jammed up so thick that you could go out there any time of evening and just get whatever you needed for your family," highlighting the species’ former ecological and cultural significance.

However, the cumulative impacts of extensive logging, unchecked development, and the accelerating pace of climate change have severely degraded the coastal streams, pushing coho salmon to the precipice of extinction. Simmons, now in his sixties, has witnessed firsthand the dramatic decline of these once-plentiful populations. In Mendocino County, situated towards the southern extent of the species’ range, the coho salmon population was officially classified as threatened by the U.S. Fish and Wildlife Service in 1996 and subsequently listed as endangered in 2005, underscoring the urgency of conservation efforts.

The presence of the young coho in the Navarro River represents a beacon of hope in a long and arduous recovery process. For the past two years, conservationists have observed a notable resurgence in coho salmon returning to the coast in significant numbers. Peter Van De Burgt, a restoration manager with The Nature Conservancy, expressed cautious optimism, stating, "Recovery seems possible. We’re on the right track." This sentiment is shared by many involved in the extensive restoration initiatives across the region.

The initial attempts to restore Mendocino’s streams for coho and other salmon species commenced in the 1960s. Decades of intensive logging in the region’s ancient redwood forests had resulted in an excessive accumulation of woody debris within stream channels, creating miles of impassable barriers for migrating fish. In a well-intentioned but ultimately misguided effort, state conservationists embarked on a campaign to remove this debris.

Anira G’Acha, environmental director for the Cahto Tribe of Laytonville Rancheria, characterized this early approach as a "Western concept, like sweeping the floor." This resulted in the creation of hundreds of miles of overly simplified stream channels, resembling fast-flowing, open "bowling-alley lanes" devoid of the complex structures that salmon require. This practice inadvertently stripped the streams of essential habitat features.

The consequences for the salmon were dire; fish populations continued to decline. "It’s hard to be a salmon," remarked Van De Burgt, emphasizing the numerous threats these fish face throughout their life cycle. From avian predators and river otters to larger fish, young salmon are vulnerable. The absence of fallen logs and other woody debris meant that streams lacked the crucial overhanging banks, shaded areas, and deep pools that provide vital cover and refuge from predators.

Gradually, a paradigm shift occurred within the scientific and conservation communities as researchers began to understand the indispensable role of woody debris in supporting salmon populations. By the time coho salmon were granted protection under the Endangered Species Act, the California Department of Fish and Wildlife acknowledged the shortcomings of their earlier efforts. John Andersen, a California forester and policy director for the Mendocino and Humboldt Redwood Companies, described this realization as a collective "Oops" moment, leading to a reevaluation of stream management practices and a renewed focus on reintroducing woody debris.

Historically, natural processes, particularly wildfires, played a crucial role in felling trees and contributing to the formation of essential logjams in stream habitats. Ron Reed, a Karuk tribal member, cultural biologist, and dipnet fisherman, explained that "Stream habitat evolved around fire for thousands of years." However, the rise of the logging industry and aggressive wildfire suppression policies disrupted these natural cycles. Conservationists were compelled to actively intervene by felling select trees to intentionally create new logjams, mimicking natural processes.

In the late 1990s, a collaborative approach began to emerge, with companies like Mendocino Redwood partnering with Trout Unlimited to restore coho habitat on their lands. This initiative soon expanded, with The Nature Conservancy and other organizations joining forces, leveraging state and federal grants to undertake stream restoration projects across the region. Halligan highlighted the formation of an "ecological system" of collaborators that has sustained this critical work, channeling significant funding into local contractors and bolstering rural economies.

Despite the growing understanding of the importance of logjams, their implementation proved more challenging than their removal. Early restoration projects often faced the same rigorous state environmental permitting processes as conventional logging operations, despite their fundamentally different ecological objectives. This bureaucratic hurdle meant that some projects took more than a decade to complete.

Practical challenges also emerged. Chris Blencowe, a forester who consults on projects for The Nature Conservancy and Trout Unlimited, shared lessons learned from early endeavors. Initially, he utilized second-growth redwoods, but observed that when these trees toppled into streambeds, they "often just break like an overweight watermelon," failing to create the stable structures needed. This led to a shift towards using Douglas fir for many projects, as it proved more resilient.

Blencowe also developed techniques to strategically wedge logs between standing trees, preventing them from being washed away during the intense winter rains, a common issue in the initial years of restoration. To address concerns about the potential harm to aquatic life, The Nature Conservancy adopted a specialized machine that uses vibrations to sink logs into the sediment, avoiding the disruptive noise of a power hammer that could stun or kill nearby fish.

Even after two decades of dedicated effort, the unpredictable nature of river systems means that not all restoration plans unfold as anticipated. Van De Burgt embraces this inherent unpredictability as a key feature of successful restoration. "We want to implement projects that create chaos in the river," he stated, explaining that this "chaos" translates into a greater diversity of microhabitats, providing more places for young coho to thrive and survive, ultimately increasing their chances of reaching the ocean.

These restoration efforts extend beyond benefiting coho salmon, positively impacting other salmonid species, including steelhead, and contributing to the health of riparian forests. Marisa McGrew, a Karuk and Yurok woman and assistant natural resources director for the Wiyot Tribe, emphasized this interconnectedness in an email, noting that felling nearby second-growth trees for logjams "encourages understory plant relatives to grow," underscoring the principle that "Stream restoration and forest restoration go hand in hand."

The winter of 2023-2024 witnessed a remarkable return of coho salmon to the Mendocino coast, with 15,000 individuals documented spawning, the highest number recorded by the California Department of Fish and Wildlife in 16 years of monitoring. Preliminary estimates suggest that this number nearly doubled in the following winter. Sarah Gallagher, who leads the agency’s monitoring program, attributed this success to a "perfect alignment" of favorable ocean conditions, a respite from several years of drought, and the cumulative impact of hundreds of miles of restored stream habitat.

Despite this encouraging trend, the current population remains a fraction of historic levels; at their peak, hundreds of thousands of coho salmon returned to California streams annually. The populations of other salmon species, such as chinook and steelhead, continue to face decline. In mid-April, the interstate Pacific Fishery Management Council extended its ban on ocean salmon fishing for a third consecutive year, reflecting the ongoing challenges. Furthermore, hundreds more miles of North Coast streams still require habitat restoration. "Sometimes, when you look at it on a map, it looks like we’ve barely done anything at all," admitted Halligan of Trout Unlimited, acknowledging the vast scale of the task ahead.

Even as the current season’s population is being assessed, the future of its habitat remains precarious. Earlier this year, the Trump administration proposed significant budget cuts to the National Oceanic and Atmospheric Administration, an agency whose Pacific Coastal Salmon Recovery Fund has been instrumental in supporting much of the restoration work, including Gallagher’s coho monitoring efforts.

In response to these funding uncertainties, conservationists in Northern California are actively exploring alternative funding mechanisms, such as the $10 billion allocated for climate resilience projects through Proposition Four, which California voters approved last November. With the initial stages of recovery underway, these dedicated individuals remain resolute in their commitment to bringing coho salmon back to their ancestral waters. As Simmons poignantly observed, the coho "are realizing this is their homeland where they were born. It seems like they’re trying to heal." This sentiment captures the profound connection between the land, the water, and the species that depend on them.