For many involved, the fisher release project has marked milestones in their personal lives.

“My son released the first fisher back into the Cascades and he's been sort of an ad hoc part of our team ever since,” says Dr. Jason Ransom, a National Park Service senior wildlife biologist and principal co-investigator. “He was pretty small when we started, and now he can carry the box.”

With this release and possibly one or two more by the end of the month, the release phase will have wound down. The team hopes to release seven or eight more in the North Cascades in January, but there are no releases planned after that, for any of the sites. Lewis says monitoring for the project will likely continue into 2021.

The fisher project begins

Slightly smaller than a Maine Coon, with a face like an elongated teddy bear and a musk Lewis describes as “tangy, rancid vanilla,” fishers closely resemble other weasel family members like martens and minks. Their toughness rivals their cousin, the wolverine: They are one of the few animals that can successfully prey upon porcupines.

Fishers historically thrived in low- to mid-elevation forests in Washington’s western half, northeastern corner and in pockets of the southeast, where they denned in craggy old-growth trees. But English settlers found big money in their pelts. A commercial trapping ban in 1933 came too late, and logging and development carved up much of the forests remaining fishers needed to reproduce.

"We didn’t have any reliable detections of wild fishers since 1969,” says Lewis, who has studied the animal for over two decades. “There was one detected at Fort Lewis, but that one had escaped from Northwest Trek Wildlife Park, so that one didn’t really count."

Even if some fishers remained undetected, scientists concluded they wouldn’t come back to full strength without a helping hand.

By 1998, the state listed fishers as endangered. Conversations among the Department of Fish and Wildlife, the National Park Service, Conservation Northwest and other groups put recovery in motion. By 2006, they developed a plan using Washington’s three national parks. Wild fishers would be procured by trappers in British Columbia, where fishers were doing well, and released in Washington.

The precise extent of the role fishers play in Washington forests is unclear, but Ransom points to activities like spreading berry seeds through digestion and eating small mammals, with younger fishers becoming prey for larger animals. And most ecologists agree that ecosystems with more biodiversity are more resilient to stressors: When multiple animals fill similar roles, food webs have a better chance of surviving the havoc of fires, floods, disease, development and other changes.

“Maybe [ecosystems are] more resilient to climate change, maybe they're more resilient to other natural disasters — that's probably all true. But the biggest reason [for the project] was these animals disappeared on our watch,” Lewis says. “It certainly wasn't anyone’s intention for them to disappear, but … they were gone before we knew anything about how to manage [fishers].”

The team first released fishers in Olympic National Park, from 2008 through 2010. A South Cascades (Rainier) project started in the fall of 2015, and in the North Cascades in fall 2018.

Animals are released outfitted with VHF radio-transmitter chips, which last up to two years. Long-term monitoring relies on hair snares and camera traps.

Those latter releases happened despite huge barriers. Wildfires broke out over B.C. fisher habitat in 2017 and 2018. Without knowing how many fishers were left, the B.C. government paused the project. With the help of wildlife officials in Alberta, a commercial air carrier and the Calgary Zoo, the team found a way to bring more fishers from that province to America by plane. “Everything worked out but there's one challenge after another,” Ransom says.

The process puts animals through considerable stress: They’re caught, transported to a vet, shipped to Washington, driven out to the forest and left to find habitat, food and mates in a foreign environment. This is where their signature toughness can be a benefit.

“When you think about all they go through, we’re asking a whole lot of them and they just do it,” Lewis says. “And they can get along with three legs and just one eye and all kinds of broken bones, and they just don't let that stop them.”