CHINOOK BEND, King County — Salmon was a gateway animal for Jennifer Vanderhoof. Her work with the Northwest’s most beloved fish introduced her to the world of the industrious beaver, a critter that can alter a landscape like no other animal except for humans.

“It’s kind of a way of life,” she said on a recent spring day while walking along the edge of a pond near Carnation, a blue heron gliding across the still, dark water and past a beaver lodge. “I’m fascinated by them.”

For many reasons, there is still much to be learned about beavers and their outsized impact on an ecosystem, but that is part of the allure.

“There is so much we don’t know,” said Vanderhoof, a senior ecologist with King County. “We spend so much trying to save salmon and that is what propelled me into this work.”

Vanderhoof doesn’t have “beaver” in her job title, but the animal once prized for its fur is dominating her work with the county. She is part of a cadre of people in various scientific disciplines who have converged to solve a puzzle: finding ways humans and beavers can live side by side.

“To me, this is the holy grail of beaver coexistence in King County. Figuring out how the beavers and farmers can coexist,” she said.


Farmers and landowners have historically clashed with beavers as they’ve dammed up waterways, flooded land and knocked down trees.

Beaver coexistence is not only good for salmon but also could have the benefit of combating the many negative effects of climate change.

Much of this beaver work is being driven to create space for the animals and to harness the power of beaver engineering to store water, recharge groundwater levels, cool waters downstream from dams and create wetlands many other species rely on. All things important in a warming world.

Rebounding population

Wildlife biologists, Native American tribes, hydrologists, and environmental and sportsman organizations are at the center of efforts to integrate a growing population of the bucktoothed, riparian-loving rodents that were extirpated from the region around 1850 and are now in a changed environment that was built up by humans without beavers in mind.

Beaver specialists say it is hard to know how many of the animals lived in North America before Europeans began streaming across the Atlantic Ocean, but estimates put the number between 60 and 400 million. After nearly being eliminated from the continent because of trapping for their fur, beavers have since rebounded. One calculation from the 1980s pegs the number between 6 million and 12 million. Another estimate from 2000 puts their population at 9.6 to 50.4 million.

By the 1920s, beavers were being relocated to Western Washington from Walla Walla, where their numbers increased, as did incidents with farmers and landowners.


It isn’t known how many beavers live in Western Washington, or King County, but the population began to grow after voters banned body-gripping traps in 2000.

Vanderhoof will soon start a project in the upper reaches of the Green River watershed that will be exploring many of these questions surrounding beavers and climate change.

Salmon might have led Vanderhoof to beavers but the issue is much bigger, she says, because what beavers do to a landscape benefits not only salmon but a variety of amphibious, ground-dwelling and airborne animals.

The trick is getting farmers and landowners on board who might be negatively impacted by beavers, she said.

“If we can find ways to solve those kinds of problems so that we can have more beavers on the landscape that can then provide the benefits for salmon recovery and climate change and biodiversity, that’s a huge win for everybody involved,” Vanderhoof said.

Beavers and climate change

Beavers became a professional interest of Ben Dittbrenner when he was working in surface-water management for Snohomish County. The hydrologist spent a good portion of his time clearing the handiwork of beavers from culverts under roads.


Beavers view the roads as the most amazing dams that need only patching up where culverts poke through, Dittbrenner said.

“There are crews that go around popping the culverts,” he said. “It is never ending and the beavers will never stop doing it.”

Watching this back and forth between humans and beavers helped spur Dittbrenner in 2013 to help create Beavers Northwest, a nonprofit focused on research, education and assisting landowners who are having issues with beavers.

Dittbrenner, now an associate professor at Northeastern University in Boston and the associate director of Beavers Northwest, focused his doctoral work in hydrology and landscape ecology because he wanted to further explore how beavers affect ecosystems and can help combat climate change.

Increasing temperatures in the Pacific Northwest mean precipitation will fall as rain instead of snow in the Cascades, in turn shrinking the snowpack that streams and rivers rely on for cool water during warmer months when rain becomes more scarce. Winter mountain rain pushes more water through streams and rivers at higher volumes, which can lead to greater erosion and flooding.

Beaver engineering can help alleviate some of these problems. Beaver dams slow water down as it courses through streams from the mountains to the Salish Sea. The ponds created behind beaver dams store water that seeps into the ground, where it is cooled by the earth.


“It’s kind of an analogue for snow storage,” Dittbrenner said. “The other issue is that the ambient temperature of the ground is fairly cool, especially compared to summer temperatures. So if that water infiltrates into the ground and is stored as groundwater, when it does emerge back out, it will have been cooled.”

A tool in salmon restoration

Others are exploring beaver relocation, efforts to remove beavers from a place that has become problematic and to areas where they might thrive.

Molly Alves joined the Tulalip Tribes’ wildlife program in 2014 — the year the tribes launched a beaver relocation project — thinking she would be working with bears, elk and cougars. Instead she “fell in love with the beaver work” and is now the tribes’ wildlife biologist.

“One of the coolest things that I’ve seen as a wildlife biologist is a beaver’s ability to transform habitat in a way that benefits all other Western Washington species,” she said.

The program might target beavers having problems blending with human neighbors, but the thrust of relocation is to help salmon.

“The main focus of the project is to essentially use beavers as our partners in salmon restoration, and habitat creation,” Alves said. “So we’re doing that because salmon are an incredibly important sustenance resource for the tribes in our wildlife program.”


Alves and her colleagues quickly realized they couldn’t handle all the calls they were fielding from throughout Western Washington, so they reached out to other tribes about assisting with beaver relocations. The Cowlitz Tribe in Southwest Washington is now in the second year of its beaver relocation project.

The cost and work of relocation was only falling to the tribes because it was illegal for anyone but tribes to relocate beavers in Western Washington. The Tulalip Tribes could do so because of their sovereign rights to work on and create salmon habitat within the tribes’ historical fishing areas that include the Mount Baker Snoqualmie National Forest, where the beavers they trap are relocated.

The Tulalip Tribes worked to get the law changed in Olympia in 2017 so nontribal entities could also do the work. The state Department of Fish and Wildlife is now responsible for the program that certifies beaver relocations. The Tulalip Tribes handle the training for the program.

More work to be done

When Vanderhoof speaks of beavers, it is like the channels that emerge around a beaver dam: The knowledge in her escapes and flows from one beaver-related topic to another, sometimes overlapping before breaking off in a new direction.

Vanderhoof’s passion for beavers is clear when she repeatedly warns others that she could talk about beavers all day.

At the beaver pond near Carnation, she points out the many felled trees while explaining how the rodents have transformed the area that was donated to the county in 2000.


The pond, in the Chinook Bend Natural Area, started to grow in 2008 when the Carnation Wastewater Treatment Plant began discharging reclaimed water to the site. The year before, the conservation group Ducks Unlimited and the county planted trees near the pond. Beavers built a lodge in the bank in 2012 and dams the following year.

The Carnation beaver pond has taught Vanderhoof a lot about beavers and has helped with the “Planning for Beavers Manual” she is writing.

Her focus is paying off. Vanderhoof secured a $500,000 grant from the state Department of Ecology to study human-made beaver dams in the upper reaches of the Green River watershed. The project’s goal is to see if beavers will use the ready-made dam complexes and if these structures increase surface and groundwater storage.

The project will also explore whether planting cottonwood and willow trees, beavers’ preferred trees, near a stream will cause them show up to nosh and build without a beaver dam analog.

Beavers have become more than work for Vanderhoof, who has a deep love for animals, especially birds. Last weekend, she came across a novel sight while “beavering” in a canoe along the north end of Lake Sammamish.

It was the first time she had ever seen a beaver family.