Beavers can affect wildfires

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Their dams create wetlands affecting vegetation type, fuel moisture, and local humidity

American Beaver
American Beaver. Photo by Steve from Washington.

The job of a beaver is to build a dam and lodge across creeks using tree branches, vegetation, rocks, and mud. They chew down trees for building material. Dams impound water and lodges serve as shelters. Their infrastructure raises the water table and creates wetlands used by many other species, and because of their effect on other organisms in the ecosystem, they are considered a keystone species.

This storage of water can change the vegetation type as well as the moisture content in the live and dead fuel. Wetlands usually do not burn in a wildfire and they can serve a barrier to its spread.

However, beavers can also be a nuisance and can damage crops, timber, roads, ditches, gardens, and pastures by cutting trees, burrowing, or flooding areas.

Wetland created by beavers Sharps Fire
Wetland created by beavers in Baugh Creek in Idaho, part of the Sharps Fire.

The website is a not-for-profit publication, “Created by Californians seeking to protect California from wildfire. We can help one another to safety by welcoming back native beavers and traditional prescribed burning of brush.”

Photos from their website show the change in a creek after beavers moved in.

Beaver dams at Susie Creek
Beaver dams at Susie Creek, from

An article by Lucy Sherriff at the Sierra Club’s website explores how beavers can change the landscape, including their effects on wildland fires.

[Dr. Emily] Fairfax began to carry out the scientific research that she had hoped to find. Using satellite images, she mapped vegetation around beaver territories before, after, and during wildfires (footage of wildfires in progress can show how a fire moves through a landscape). She visited field sites in California, Colorado, Idaho, Oregon, and Wyoming and found sections of creek that did not have beavers were on average more than three times as affected by fire—burning a bigger area—than areas where beavers had built dams.

“I expected some of the time beaver dams would work,” says Fairfax. Instead, she found the presence of beavers had significant effects. “It didn’t matter if it was one pond or 55 ponds in a row. If there were beaver dams, the land was protected from fire. It was incredible.”

Fairfax hopes her research will help change California’s strict rules around beaver relocation, the way policy is already changing in Washington, especially as wildfires in California have reached record-breaking levels over the past several years.

Meanwhile, Fairfax’s research on beavers and wildfires is only beginning. “I set out to ask a question: Do beavers keep the land green during fires, yes or no?” she says. “The answer was yes. But that’s not the end of the story. Why? How? Does this happen everywhere? What if you have a tight canyon? I’m digging into the specifics now, so people can implement this and actually use beavers for fire prevention. I would love to be able to call someone up and tell them how many beaver dams they need in their creek.

“Right now I have so little advice on how to do it. But at least I can now say it works.”

The two-minute video below is a brief introduction to beavers. It appears to be an excerpt from an episode of “Nature”, titled, “Leave it to Beavers.”

Typos, let us know HERE, and specify which article. Please read the commenting rules before you post a comment.

Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire.

7 thoughts on “Beavers can affect wildfires”

  1. The natural environment can often take care of its self with out human help.

  2. Years ago in Oregon a beaver case went to court and established beavers’ water rights, in effect, after one neighbor sued another neighbor over water rights affected by the beavers’ enthusiastic landscaping on the upstream neighbor’s acreage.

    1. Any flyfisher worth knowing also knows that beaver ponds are usually fun and productive. See Gierach, John.

  3. In the 1940’s the Idaho Department of Fish and Game trapped beavers and transplanted them into the Frank Church River of No Return wilderness. They were dropped out of a plane in boxes attached to a parachute. The box would open when it landed and the Beaver would crawl out. would open when they landed. A film showing the technique was lost for 65 years but was found a few years ago. A short exert from the film and more information here.

    I remember seeing a comic book years ago the Forest Service would hand out that told the story of the parachuting beavers.

    1. In 1988 as the Yellowstone fires were winding down in October/November, we moved beavers with slingloads under helicopters, into drainages. We were working on the Hellroaring Fire then on north side of the Park. We called it “slinging wet beavers”. I am not sure the beavers had time to establish dams and food stores before winter, and may have worked better in the spring.

  4. Active Beaver dams and especially their houses often make for excellent access on Initial Attack. They are solid, there is always significant deep water for your pump and it usually clear enough to toe in with helicopter.


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