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Beavers Used to Be Almost Everywhere in California

by on June 19, 2014

Photo: Jason Miles/Flickr
Photo: Jason Miles/Flickr


oseph Grinnell was one of California’s preeminent twentieth century zoologists, responsible for a good part of what we know today of the historic ranges of the state’s native fauna. But even Grinnell had blinders — or maybe it was the limitations of an analog world.

Grinnell, and his contemporary naturalist Donald Tappe, thought that beavers had a limited range in California, and never inhabited much of the state’s coastal areas, including the San Francisco Bay Area or the Sierra Nevada mountains.

In the 60-plus years since the two naturalists drew up their beaver range maps, surprisingly little has changed in the state’s official outlook. For the most part, Castor canadensis is considered a non-native pest, and subject to state-permitted removal from backyard streams, or anywhere else people find it inconvenient.

But in a new paper recently published in the scientific journal California Fish and Game, a group of hobbyist and professional ecologists rethink Grinnell and Tappe’s assessment. They’ve compiled evidence from a wide range of digital and paper archives to show that beavers were once prevalent throughout most of California, including the entire San Francisco Bay Area.

Image: Eli Asarian, Riverbend Sciences.

Image: Eli Asarian, Riverbend Sciences.

Their findings suggest a different ecosystem prior the arrival of Western settlers, one in which beavers may have been critical to the creation and maintenance of an extensive network of wetlands throughout California that were teeming with life. After all, beavers are renowned “ecosystem engineers,” and wherever they appear so do many other species.

“All of San Jose was a gigantic wetland with tens of thousands of elk and huge flocks of waterfowl that would have darkened the sky. That would have been true for the Marin coast as well,” said one of the paper’s authors, Rick Lanman, a physician by trade who has more than a passing side-interest in the historical ecology of California (Lanman’s son, Chris, a recent high school graduate, was the lead author). “We have the least understanding of any state on what used to live here.”

Including beavers.


ust how California got its natural history wrong all these years has to do with our collective amnesia. Much of our knowledge of California’s ecological past is being reconstructed today, as early records and specimens are being uncovered around the country and the world.

When Grinnell published the definitive Fur Bearing Mammals of California in 1937, mammals such as beaver were long gone, the paper contends.

“Everything had been wiped out 75 to 100 years before Grinnell started writing,” said Lanman. “He’s a great guy, he made tremendous contributions, but he was limited. He didn’t have digital records. You can search from your desktop online now.”

Grinnell and Tappe reasoned that beaver were absent south of the Klamath River watershed because the climate is more arid, and coastal “stream beds are for the most part rocky and steep with but little beaver food growing along them ….” They also excluded the Sierra Nevada above 1,000 feet in the rivers draining into the Central Valley. But this made little sense to Lanman and his colleagues. Beavers have been found in riversheds as arid as the Mojave River, and recently they have been recolonizing many rivers and watersheds in the Bay Area.

“I knew this assumption that beavers were never in the Bay Area was bogus just from life experience. There was a beaver right under I-680 when I would drive home. I knew they were there,” said Heidi Perryman, one of the paper’s authors.

Often people are worried that beavers will flood out areas, but there are ways to ensure water levels don't get too high. Photo: Cheryl Reynolds/Worth A Dam

Often people are worried that beavers will flood out areas, but there are ways to ensure water levels don’t get too high. Photo: Cheryl Reynolds/Worth A Dam

Perryman founded the beaver advocacy group, Worth a Dam, to save from extermination a beaver family that had moved into a highly-visible pond outside a Starbucks coffee shop in downtown Martinez in 2007. City officials thought the beavers were a flood hazard and didn’t belong there. It’s a reaction that beavers get time and again, and is often legitimized with depredation permits. In 2013, the California Department of Fish and Wildlife issued 172 depredation permits, each one allowing the removal of multiple beavers on an individual site.

Perryman said that over the years she’s heard the case against beavers, premised on the notion that they are not native.

“People convince themselves that things weren’t there, or aren’t there anymore,” she said. “This probably has a hint of meaning in beavers.”

If that notion could be disproved, maybe it would change the nature of the debate. In 2012, Perryman, Lanman and Brock Dolman from the Occidental Arts and Ecology Center’s Water Institute wrote their first paper reviewing the evidence for beavers in the Sierra Nevadas.

“We had to step in and address this assumption that beavers are not native, therefore we can consider them to be a danger, a nuisance and then lethal management is justifiable,” said Dolman. Occidental’s Kate Lundquist was also an author on the paper and contributed to the research.

So, they got to work.


he group cast a wide net, searching for specimens in museums and archaeological sites, and examining historical fur-trapping records, historical newspaper accounts, geographic place names, and Native American tribal names for “beaver.” They turned up a treasure-trove of evidence.

Beaver bones are found in many places, including the Emeryville Shellmound, located on historic Temescal Creek, where a beaver tooth was catalogued at AD 300-500, as well as three other beaver bones. A rock painting from the Tule River Indian Reservation in the Sierra Nevada depicts what can only be deemed a beaver, dated at 500-700 years old.

A rock painting depicting beaver by the Chumash tribe, located at 1,600 feet elevation in the Sierras. Image courtesy of Heidi Perryman.

A rock painting depicting beaver by the Chumash tribe, located at 1,600 feet elevation in the Sierras. Image courtesy of Heidi Perryman.

Then there are the place names: Beaver Creek, Beaver Ridge, Beaver Butte, Beaver Flat (Humboldt County), Beaver Point (Mendocino), Beaver Campground (Ventura), Beaver Hollow (San Diego).

Coastal Native American tribes had words for beaver. The Wappo in Sonoma called them “ma’-nah ow’-we,” the Coast Miwok, “kah-ka’,” and the Rumsen Coastanoan in Monterey called them “sur-ris,” among others.

But it’s the historical records the group dug up that tell the fuller story of what happened to California’s beavers. In short, they were trapped out of existence. As the United States was just forming as a nation, the California coastline was an economic free-for-all with American, Spanish, English, and Russian ships sailing in to procure various kind of mammal pelts from the Native American tribes. Sea otters and seals were the primary target, but beaver pelts were desirable too.

Beaver fur was once very popular hat-making material. Photo: Don Sneigowski/Flickr.

Beaver fur was once very popular hat-making material. Photo: Don Sneigowski/Flickr.

The authors date the start the California fur trade to 1785, just a decade after the Spanish discovery of the San Francisco Bay. Among the references to beavers were ship logs from commercial vessels listing beaver pelts on board. On the ship Albatross: 248 beaver pelts. On the Russian ship Kodiak’s journey back from Bodega Bay in 1809 were otter and beaver skins.

Even further back in time, when the second Anza expedition was sent to found the Presidio in San Francisco, it stopped by the wetlands where the  Mission Dolores would soon be established. On June 22, 1776, Father Francisco Palou described  that the Native American men covered their shoulders “with sort of a little cape of beaver skins and pelican feathers.” French sea captain August Duhaut-Cilly wrote in 1827 of the Native Americans at Mission Sonoma that “the young men are letting fly their arrows at the beaver.”

The authors argue that the beaver were largely finished off by overland fur trappers. In 1821, the British-owned Hudson’s Bay Company set out from its bases in the Pacific Northwest to search as far south as the Sacramento and San Joaquin valleys with orders to denude the lands of all fur-bearers so that the Americans would “have no inducement to proceed hither.”

In an 1829 progress report on the company’s first fur brigade, Alexander McLeod reported that: “Beaver has become an article of traffic on the Coast as at the Mission of St. Joseph (in Fremont) alone upwards of 1,500 beaver skins were collected from the natives at a trifling value and sold to ships at $3.” In one year, the Hudson’s Bay Company took 4,000 skins from the shores of the San Francisco Bay.

The authors noted that Native Americans would have been able to hunt beaver in mass numbers once maritime fur traders provided them with iron traps and guns, as traders did on the Eastern seaboard. By 1841, the numbers of fur-bearing animals had been so depleted along California’s coast that the Russian American Fur Company sold Fort Ross in Sonoma County just 30 years after its establishment.

Inland beaver populations took longer to exterminate, but they were largely trapped out of existence except for the Sacramento-San Joaquin River Delta, where beaver were able to live largely undetected because of deeper waters. It may be that Grinnell and Trappe limited their analysis of the state’s beaver range to the remaining areas where beaver could still be found at the time of their writings.

“We felt the missing piece was that coastal beavers were never as numerous in numbers (as otters), and a group of native folks set on capturing them wouldn’t have taken long to eradicate them, especially in riparian systems where there is not a lot of room to move,” Dolman said.


t is perhaps because of their longtime absence that beavers are so overlooked as a solution to today’s conservation problems. Need help restoring a wetland, or recharging groundwater? You could bring in a beaver. Does your river dry out for half the year? A family of beavers might fix that. Are you trying to bring back salmon populations, or red-legged frogs? Beavers.

“I’m not OCD on beaver here,” said Dolman. “But they are a tool in the toolbox. They have the capacity to provide a level of service to the ecosystem that is better and more durable and cheaper than we can do.”

In an interesting historical footnote mentioned in the paper, California brought back some beavers to stem erosion from 1923-1950, bumping the statewide population from a dwindling 1,300 in 1942 to 20,000 by 1950. The translocations happened in 58 counties — including Marin, Napa, Contra Costa, Alameda, San Mateo and Santa Cruz — and are thought to be responsible for the beavers that live here today.

Beavers are responsible for creating biodiversity hotspots. Photo: Cheryl Reynolds/Worth A Dam

Beavers are responsible for creating biodiversity hotspots. Photo: Cheryl Reynolds/Worth A Dam

As beavers bring up mud, they diversify the habitat for invertebrates on the pond floor, and set the stage for a thriving food web. Photo: Cheryl Reynolds/Worth A Dam

As beavers bring up mud, they diversify the habitat for invertebrates on the pond floor, and set the stage for a thriving food web. Photo: Cheryl Reynolds/Worth A Dam

So, it’s not a crazy idea that beavers could be brought in again to help mitigate twenty-first century problems like climate change-induced droughts and water shortages. In southern Utah, the Grand Canyon Trust is reintroducing beaver to 87 creeks and waterways in the national forests.

“I wish people had been talking about [this] when California declared drought this year,” said Perryman. “People need to be thinking about the animal that keeps water on the land as a resource.”

In fact, there’s a growing interest among scientists to do just this. The Nature documentary film series recently produced an hour-long show,  “Leave it to Beavers,” about how beavers can revive a landscape.

It may be that beavers’ day may come again to California.

Check out these Napa beavers.

Alison Hawkes is the online editor of Bay Nature.

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Bev Jo on June 19th, 2014 at 6:18 pm

This is SO important. Thank you!

This article explains so much and calls the nativist “environmentalist” lies into question once again.

They tell us beavers are not native (sound familiar?), so kill them, remove them, etc., even though we would have lakes and ponds throughout our arid, drought-stricken state if the beavers returned.

They only now figured out that beavers are native, based on ancient rock paintings, Indigenous California nations have words for beavers, and beaver bones found in ancient shellmounds and other sites?

Doesn’t this mean that anything the nativists say that make no sense or is harmful to our environment should be not believed?

In arid California, beavers would have had an amazing effect on migratory birds, resident birds, amphibians, reptiles, mammals. crustaceans, fish….

Lakes and ponds are so important in this place that gets no rain for 5 or 6 months each year and which often has droughts where creeks dry up, leaving no water for the animals or plants. (Not to mention that so much of the water is diverted to LA.)

I’ve wondered why there are almost no lakes of ponds here except the reservoirs made for humans, and small ponds made by ranchers for cattle. At Pt. Reyes National Seashore, there was a beautiful little lake where egrets nested, kingfishers hunted, muskrats lived, and many other animals lived in or relied on the water. But it wasn’t native, so the “environmentalists” destroyed it. It is heart-breaking to see where it was. The trees lining the dam are gone, the bridge, the trail connecting to other trails, the animals…. all gone.

But if the beavers had not been hunted almost to extinction, and not killed when trying to return, we all (the other animals) would have many more lakes and ponds because the beavers would create them from the rivers. Of course this would affect the water stolen from the north by the rich….

Please spread the word for government agencies to return our largest North American rodent and make California wetter and supporting the many species who used to live here. And spread the word to stop the nativist lies….

Mary McAllister on June 19th, 2014 at 7:10 pm

This is interesting information about beavers in California and I hope the understanding that it is native to California will help to protect it. However, I fear that it won’t. US FWS reported killing over 4 million animals last year and half of them were native. There’s a story in the Guardian about this and here’s a quote from it:

“But Wildlife Service also kills native animals en masse, sometimes based solely on a homeowner’s or farm owner’s perception of a threat. 2013’s toll of 2 million native American animals included 75,326 coyotes, 866 bobcats, 528 river otters, 3,700 foxes, 12,186 prairie dogs, 973 red-tailed hawks, 419 black bears and at least three eagles, golden and bald.”

The fact is, when animals get in the way of humans any excuse in the book will do. Actually the main point of the Guardian story is that US FWS won’t even say why they killed most of these animals. Since beavers are “ecosystem engineers” they can and do alter landscapes by turning rivers into ponds and marshes, which can be inconvenient for humans who want things to look a certain way and they don’t like changed.

Don’t get me wrong…I don’t condone the killing of beavers or any other animal, native or not. I just see it happening around me everywhere and am hoarse with protesting to deaf humans who have only their own interests in mind.

Heidi Perryman on June 19th, 2014 at 8:04 pm

Thanks so much Alison for this awesome and much-needed article. If folks want to learn all about beavers in California they should visit our 7th beaver festival August 2 https://vimeo.com/98180014 where you will be able to see first hand the good they’ve done for Alhambra Creek!

Here’s the promise California should be making:

I pledge allegiance to the streams
And the beaver ponds of America
And to the renewal for which they stand
One river, underground, irreplaceable,
With habitat and wetlands for all.

Heidi Perryman
Worth A Dam

Walt Anderson on June 19th, 2014 at 8:55 pm

Thanks for this valuable article. I am working to educate and promote beavers here in arid Arizona (there are more on the Verde River than you might expect). I am appalled by the destructiveness of Wildlife Services, but I want to correct something in Mary McAllister’s comment. USFWS is the US Fish & Wildlife Service, which is in the Dept. of the Interior and not to be confused with Wildlife Services, which is in the Department of Agriculture. The names are confusing, but we don’t want to blame the wrong culprit. That said, please do everything you can to stop Wildlife Services from their secretive and unconscionable attacks on native wildlife (they do kill non-natives, too). Center for Biological Diversity is one group mounting such a campaign.

Susan Kirks on June 19th, 2014 at 8:58 pm

EXCELLENT – thanks to Bay Nature, Brock and everyone at OAEC, and Heidi, Cheryl and Worth a Dam, and Rick Lanman and his son, Chris, et al. Exactly the featured information so helpful for all to read, so Alison, thank you, again, to Bay Nature. And to these dedicated biologists and conservationists who know the importance of beaver to our ecosystems and have devoted extraordinary time and energy to protect the species and help others understand the importance of beavers to our world.

Duane Nash on June 20th, 2014 at 12:29 am

Excellent article and salient points in the comments as well. Unlike human dams and diversions beaver modifications allow habitat hetorgeneteity and connectivity. Many of the most imperiled animals on the west coast such as steelhead, coho salmon, western pond turtles, red-legged frog, pacific lamprey and numerous birds use beaver ponds during most or all of their life cycles. It is not unfeasible that the decline in these organisms has occurred in lockstep with declining beaver populations in tandem with human disturbances. Additionally beaver benefit humans through raising the water table, mitigating flood and drought damage, and enhancing fisheries. The dual benefit to human and wildlife that beaver offer suggest a most pragmatic solution to dropping water tables and loss of habitat in California and the west.

Duane Nash

Sherry Guzzi on June 20th, 2014 at 10:03 am

Really great article on Beavers in California – informative and informed! Glad to see credit given to Rick Lanman, Heidi Perryman, Brock Dolman and others who spent countless hours gathering information to establish that beavers are native to most of California and the Sierra – which allows our group and others to promote the many benefits of beavers to our watersheds. Great photos by Cheryl Reynolds of Worth a Dam too.

Brock Dolman on June 20th, 2014 at 3:52 pm

Glad to see so many people have found this article highlighting the critical results from our collaborative & peer reviewed papers re-evaluating the historical range of beaver in California to be informative.
For those who want to get into more detail than can be published in the DF&G Journal – we want to bring to your attention a newish report that OAEC’s WATER Institute has written titled: The Historic Range of Beaver In The North Coast of California: A Review of the Evidence – find it here: http://www.oaecwater.org/historic-range-of-beaver-in-north-coast-report
Also we would like to bring to the attention of Citizen Scientists and others who have observed signs of beavers and would like to help document the extant distribution of beavers in CA to consider submitting your observations on the special website created by Eli Asarian called Beaver Mapper: http://www.riverbendsci.com/projects/beavers
For more information on our Bring Back the Beaver Campaign – go here: http://www.oaecwater.org/beaver

Gail Sredanovic on June 20th, 2014 at 4:06 pm

Hooray. Great article. Prent it in a book, on a banner, on a wall. We need the work of beavers to help in a time of drought.

Just in Beaver Makes a Comeback | NatureOutside on June 21st, 2014 at 6:31 pm

[…] Beavers Used to Be Almost Everywhere in California […]

a.k. andersen on November 12th, 2014 at 11:00 pm

Interesting article. As a Boy Scout around 1960, we camped at Little Rock Dam just outside Palmdale, almost every other weekend.

We always made it a point to hike up the creek that feeds the lake at least once per trip. The creek seemed to always have water in it and we were in search of trout.

At some point the Department of Fish and Game introduced beavers to the stream. They seemed to thrive and we had a new reason to hike the canyon to see what progress they had made with there dam and the new pond formed.

Unless there was major weather activity, the flow of the stream remained fairly constant and not a threat to their existence. We kinda felt that at some point predators like coyotes, bobcats or bears would be the downfall of this family and were shocked when we found out what really happened.

On one of our hikes we discovered the beaver had vanished. Sad since they really seemed to enjoy their new surroundings and with no homes around were no threat to anyone.

On our way home we stopped a Game Warden and asked him what happened. Someone with a rifle had shot one of the beaver and just left it there.
No explanation. No reason for anything like this, just stupidity.

Fish and Game removed the other beaver for fear of more of the same. In later years the road that traveled along the creek all the way up to Angeles Crest was closed. I’m not sure if it still is I haven’t been up there for years.

The stream and canyon are beautiful and may still be viable for re-introduction. If it ever happens I may be the first in line for this way overdue hike, it’s been over 50 years.

Alison Hawkes on November 13th, 2014 at 1:12 pm

@a.k.Andersen What a sad story! I’m wondering how often this sort of thing occurs, and it’s curious that officials chose to remove the other beaver rather than let them tough it out there. Let me know if you ever see them again.

Rick Lanman on November 30th, 2014 at 5:18 pm

Thanks to Alison for a well-researched article. Our Calif. Fish and Game article was an example of a group of dedicated biologists and other professionals who cared to question long-standing opinions regarding our native fauna. Much of California’s historical fauna was wiped out by the initial Spanish settlers and likely by Native Americans incited to obtain beaver pelts for the Hudson’s Bay Company, Russian and American ships that frequented the coast. From the American occupation in 1848 to the building of the state’s first museums (the Academy was destroyed in 1906) in the early twentieth century, much of our native species were lost. I recently read an article in Science Daily stating that coyote were not native to California and followed the wagon trains here. I’m not making this stuff up. Lastly, the beaver on Little Rock Creek may still be there – someone should check for beaver sign!

john on July 28th, 2015 at 1:25 pm

i just found a watershed created by beavers upper santa ynez river, possibly saving some wildlife from death in this drought

Bill Klipp on July 15th, 2016 at 1:52 pm

In the sloughs around Discovery Bay in the California Delta east of San Francisco resident beaver families are fairly common. Here is a video from the other night: https://youtu.be/LTycDALW_Uo

Ricardo Calderon on April 29th, 2017 at 11:30 am

I saw a beaver at Camp Pendleton in Oceanside, California last month. Unfortunately it had been hit by a car. The beaver dams and huts are still there.

Ricardo Calderon on April 29th, 2017 at 11:55 am

The location I saw the beaver was in Oceanside, CA in Newton Canyon adjacent to the Santa Margarita River. Pretty far south.

MrjFlyer on September 12th, 2017 at 3:04 pm

To bad I have herd about those beaver in camp pendelton . They had mad a larg pond that held southern California steel head.

William E. Robert on December 8th, 2017 at 2:13 pm

Glad to see the beavers coming back. The climate change mentioned in the article is complete krap, though.

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