Beaver Facts

There has been confusion about where in California beaver historically lived. Many still refer to analyses conducted in the 1940s that assert beaver were only native to the Central Valley, the Klamath and the Colorado River basins.

The WATER Institute joined efforts with a group of beaver advocates to re-evaluate the historic records and publish peer-reviewed papers summarizing the physical, historic, and ethnographic evidence we found. This evidence suggests that beaver historically ranged across much of the state. The physical evidence includes buried beaver dams in the Sierra Nevada (carbon dated to 530 A.D.) and buried beaver bones in the San Francisco Bay Area and the north coast of California. Numerous historic accounts from explorers, sea captains, and trappers arriving to the state first by boat and later on foot suggest beaver were found across the state, including the Sierra Nevada mountains and as far south as San Diego county. Ethnographic evidence includes a word for beaver in sixty native California languages, beaver stories, their parts used for ceremonial objects, their bones found in middens, and their distinct image portrayed in the pictographs of native California tribes. To learn more, see our peer-reviewed published papers.

Humans have utilized beaver for food, pelts, medicine and fur for millennia. While Europeans were hunting Castor fiber nearly out of existence, Castor canadensis was still flourishing across the North American continent. Scientists estimate that there were between 60 and 400 million beaver on the continent prior to European colonization. Millions of beaver dams and ponds covered more than 300,000 square miles in pre-Columbian America. A tenth of the total land area was rich, ecologically diverse wetland, creating a mosaic of habitat for insects, amphibians, fish, birds, and mammals.

Most accounts of fur trapping in California begin with the 1826 arrival of mountain man Jedediah Smith who came in on foot from the east. We have found new evidence that suggests sea-going trappers had already begun to hunt and trade furs on the coast as early as the 1790s. Russian, American, and European fur traders sailed up and down the coast trapping and trading for whatever furs they could find. It appears from the historical records that by the time overland explorers reached California, most of the coastal populations of fur-bearing animals had already been exterminated.

There was no effort to conserve beaver while they were being trapped out of California from the 1780s to the 1850s. Quite the opposite occurred in fact. Between 1823 and 1841, the Hudson’s Bay Company ordered their employees to create a “fur desert” in the west in order to edge out competing trapping companies. The high demand for fur during this period drew so many people to the west that Dr. Rick Lanman has dubbed this era the “California Fur Rush.” Soon the Fur Rush gave way to the Gold Rush, and by the early 1900s, there were an estimated 1,000 beaver left in the state.

Beaver trapping laws were mostly unchanged until 2019 when recreational and commercial trapping were outlawed with the Wildlife Protection Act.

Recognizing their fragile status, the California Division of Fish and Game (as it was called at the time) passed a law in 1911 to protect the remaining beaver from being killed. Once beaver population numbers started to climb, the law was revised to allow the killing or “depredation” of nuisance beaver by landowners suffering damage to property. Agriculturalists in the California Delta were concerned about beaver “endangering or destroying the levees or other protective works of any reclamation, levee or swamp-land districts.” Beaver numbers again decreased and the ban on killing was reinstated. By the mid-1930s the landowner’s right to seek a depredation permit was restored for a final time and still stands today.

From 1923 until 1950, the California Division of Fish and Game recognized the benefit of beaver dams to soil, water, and wildlife conservation and initiated an extensive translocation program to repopulate the state with this helpful watershed engineer. California Fish and Game biologist Donald Tappe wrote in his 1942 Status of Beaver report that “It is now understood that soil erosion and shortage of water in some places resulted from the destruction of the beavers which formerly built, and kept in repair, dams on the upper reaches of many streams.” 1,221 beaver were live-trapped and delivered to watersheds across the state, and were even dropped from airplanes into the El Dorado National Forest using boxes with parachutes attached! Some of our beaver colonies today descend from those transplanted during translocation programs.