Beavers Build Back Better

The trails through Frijoles Canyon in New Mexico’s Bandelier National Monument are steep and narrow. They were carved into ancient volcanic rock alongside Frijoles Creek, which has sustained life in the canyon for over 400 years. Nearly 200,000 visitors come annually to see the scenic landscape with its Ancestral Puebloan dwellings, petroglyphs, and cavates carved into the volcanic tuff canyon walls. However, in the years following the 2011 Las Conchas Fire, one of New Mexico's largest wildfires, Frijoles Creek began drying up.

Though scientists at first hoped that the ecosystem would repair itself, the damage proved too significant for any noticeable ecosystem revival. The fire's aftermath left the creek carved down to solid rock in some sections, creating conditions where rainwater rushed through at higher temperatures and velocities.

That's when a team led by Sarah Milligan, natural resources program manager at Bandelier, decided that they would have to step in. They tried traditional restoration methods such as planting native vegetation and installing erosion barriers, but the effects of the fire were still extensive. Vegetation was slow to grow back, meaning that the small amount of water that Bandelier gets each year was still moving through the landscape too quickly. The team decided to enlist the help of some of the most skilled construction workers of the animal kingdom: beavers.

"These beavers are ecosystem engineers and much better at restoration than we are," Milligan explained. 

Once it was decided that the beavers would be a key part of the restoration process, it was just a matter of testing out relocation methods. The canyon's steep terrain and series of waterfalls make vehicle access impossible, so volunteers carried the beavers on their backs. It's demanding work: Beavers can reach up to 70 pounds and move around within their transport containers. Workers and volunteers are required to have a partner to switch off with, as well as hiking poles to keep their balance.

The beaver relocation process involves close coordination between Bandelier and New Mexico Department of Game and Fish wardens, who respond to calls from landowners dealing with nuisance beavers damaging their property. Rather than euthanizing the animals (the previous standard practice) wardens can now trap the beavers and meet the Bandelier team for transfer.

Once at Bandelier, staff hike the captured beavers roughly 2.5 miles up Frijoles Canyon to the release site, where the animals then disperse both upstream and downstream to establish new territories. The program has created a win-win situation for landowners with nuisance beavers, who generally prefer that these animals be relocated rather than killed.

Once beavers are in an area like the Frijoles Canyon, they’re able to raise the water table and create floodplain connectivity. After the Las Conchas Fire removed vegetation and created water-repelling soils that caused destructive flash floods, the beaver dams helped fundamentally change how water moved through the canyon. Instead of rapid runoff and channel entrenchment, the beaver dams slowed water flow and allowed groundwater to saturate the surrounding soils. As a result, the ecosystem is now better at retaining water both during flash floods and drought periods. It’s a huge step in restoring the natural hydrological function of the region that took a hit when beavers were originally trapped en masse in the 1800s. 

The team in Bandelier is not the only one to implement beaver-assisted ecosystem revival. Alexa Whipple has been doing this work since 2019, when she took over as director of the Methow-Okanogan Beaver Project in Washington state. Early efforts to relocate beavers to remote headwater systems did not go as planned at the beginning, as the environments were too depleted to support them. It took over a decade of trial and error for researchers to figure out best practices for relocating beavers to places where they would have a real chance of survival. 

Now, Whipple's organization combines relocation with habitat restoration and community coexistence programs, recognizing that moving beavers is only successful when the receiving ecosystem can sustain them and neighboring communities understand their value.

Relocation is not as simple as leading beavers into any source of water. Some critical factors determine how much success beavers will have to survive in an area, including water depth, protection from predators, food resources, and available woody vegetation for creating dams. Equally important is the community buy-in and acceptance of beavers. 

In New Mexico's agricultural communities, where elaborate networks of irrigation ditches have channeled water for farming since the 1600s, beavers represent a direct threat. When beavers encounter these waterways, they build dams, disrupting the carefully managed flow that farmers depend on. "Farmers by and large are quite opposed to getting beavers back into areas," explained Reid Whittlesey, a restoration ecologist working on beaver projects across New Mexico.

The irony is, while beavers could help secure long-term water availability, their short-term impacts on agricultural infrastructure can create immediate conflicts. This is why, perhaps, the relocation process has had such a hard time getting off the ground. “There is this generational amnesia of what a healthy condition looks like,” said Whittlesey. “North America had like 200-plus million beavers . . . the hydrologic systems ubiquitously were governed by beaver.”

Whipple and her team at the Methow-Okanogan Beaver Project address this human component directly, working to find common ground with people in the community and build rapport while educating people about the importance of beavers in the ecosystem. She said that they have found some buy-in as her community increasingly recognizes the dangers that water scarcity and wildfires can bring in an already degraded ecosystem. “Our most committed volunteers help us with our beaver husbandry when we relocate beavers and hold them in a facility while we try to capture an entire family. . . . We check on them twice a day, feed them every day, change their water. It takes a lot of people to keep them healthy."

Even though the progress may not be linear in other places, experts are hopeful, given the promising results at Bandelier. According to Milligan, the next phase involves introducing additional trees into the moisture-rich habitat that the beavers have established, with the goal of lowering water temperatures. The team also plans to conduct restoration activities in Capulin Canyon, working toward conditions that would eventually support beaver reintroduction in that area as well.

The ecosystem response has also had a sort of domino effect. "We see every species of fauna use these ponds. All are documented on camera—lions, bears, birds (even a kingfisher!), bobcats, coyotes—drinking from the ponds," Milligan reported. "The bears and birds frequently bathe in them as well. The vegetation has flourished, and we now have suitable habitat to reintroduce our endangered New Mexico meadow jumping mouse."

The beavers have demonstrated their value even during severe weather conditions. Milligan noted that footage from a major flood in September showed how the beaver dams reduced water flow velocity before it could impact the park's visitor center area. The beavers were observed repairing their damaged structures the following evening. While the team continues gathering long-term vegetation data, they have already documented increased wetland habitat and plant life, with the waterway now maintaining a more sustainable flow rate.

Over time, Milligan has realized what is needed for success, both for Bandelier and for other fire-damaged landscapes. "The biggest thing is the vegetation component before reintroduction—is there enough for them to eat and use to build?" For now, it’s up to communities, volunteers, and ecologists to learn from and lean on one another to try to bolster this keystone species, ensuring the well-being of their habitat for generations to come.