Five conservation groups have issued a notice of intent to sue over the U.S. Fish and Wildlife Service’s decision not to protect the West Coast fisher population in Northern California and southwestern Oregon under the Endangered Species Act. The groups are the Center for Biological Diversity, Defenders of Wildlife, Klamath-Siskiyou Wildlands Center, Environmental Protection Information Center and Cascadia Wildlands. The notice signals a planned legal challenge; materials released so far do not detail a court complaint.
The West Coast has three isolated native fisher populations: two in the southern Sierra Nevada and one in Northern California and southwestern Oregon, according to the Center for Biological Diversity. Small reintroduced populations are also found in parts of the central Sierra Nevada, southern Oregon Cascades and Washington. The group says historic fur trapping and logging sharply reduced native populations. Fishers depend on mature and old-growth forests, which have continued to shrink. Chelsea Stewart-Fusek, an attorney at the center, said the group views the agency’s repeated decisions against listing as unsupported by science.
A Two-Decade Pattern of Delay
The listing process began in 2000, when the Center for Biological Diversity and allies petitioned the Fish and Wildlife Service to protect West Coast fishers under the Endangered Species Act. In 2004, the agency found that fishers warranted threatened status throughout their range, but did not complete a listing. It reversed course in 2016 and denied protection, a decision conservation groups successfully challenged in court, according to the U.S. Fish and Wildlife Service's 2016 withdrawal notice.
In 2020, the Service listed the Southern Sierra Nevada population as endangered but left the Northern California-southwestern Oregon population unlisted. The agency’s distinction between the populations is described further below. Separately, Missoula Current reported that a 2014 proposed rule had found the West Coast fisher met the definition of a threatened species before the agency reversed course. The outlet described the unprotected Northern California-southwestern Oregon population as the largest remaining population and reported severe habitat loss and fragmentation from logging and wildfires.
The 2022 Lawsuit and a Broken Promise
In 2022, the Center for Biological Diversity, Environmental Protection Information Center and Klamath-Siskiyou Wildlands Center brought another challenge to the agency’s decision on West Coast fishers. The Fish and Wildlife Service agreed to reconsider whether the population warranted endangered or threatened status, with an August 21, 2025, deadline, according to Courthouse News.
By the deadline, the Service had again found that listing the Northern California-Southern Oregon distinct population segment was not warranted. The groups’ notice of intent challenges that determination. Threats they cite include wildfire, vegetation management such as salvage logging, and rodenticide use.
How the agency’s decisions differ
The agency announcement described above gives the outcome of the August 2025 finding, but the materials cited here do not lay out the evidence or reasoning behind it. The Fish and Wildlife Service’s Federal Register account records that its May 15, 2020, rule listed the Southern Sierra Nevada distinct population segment as endangered while finding the Northern California-Southern Oregon segment did not warrant listing. The decisions concerned separate population segments, not a single West Coast-wide listing. The same account says the Center for Biological Diversity, Environmental Protection Information Center and Klamath-Siskiyou Wildlands Center filed a separate complaint in federal court in Northern California on September 13, 2022. A court-approved settlement required the Service to issue a new 12-month finding by August 21, 2025.
Groups Say the Science Points One Way
The groups argue that the Service should base its decision on its scientific findings rather than timber-industry interests. They point to rodenticide poisoning and habitat loss associated with logging and fires, and contend that the agency’s assessment supports Endangered Species Act protection.
The groups also criticize the Trump administration’s management of fisher habitat, arguing that logging removes older forests and that worsening wildfires linked to human-caused climate change add pressure on the species, formally known as Pekania pennanti. A USDA Forest Service study found a significant decline in old-growth forest area across California, Oregon and Washington during the second half of the 20th century.
The Center for Biological Diversity, which says it has more than 1.8 million members and online activists, is leading the challenge with its four co-plaintiffs. Materials released so far describe a notice of intent to sue but do not detail any subsequent court filing.
