Sawtooth Association

The Alpine Examiner

December 1, 2023

Naturalist Blog

Getting to the heart of what matters in the Sawtooth National Recreation Area

Furry Banknotes:
History of Fur Trapping and its Environmental Impact

Within the academic discipline of history there are different niche genres such as military history or political history. One of the lesser-known genres is environmental history, the study of humans and their interactions with the natural world. These interactions range from appreciation to destruction. There are beautiful examples in which humans have shown their appreciation for the natural world, such as environmental activism. Sadly, there are just as many examples of how humans have wreaked havoc on their surroundings. One example of destruction in the American West was the fur trade and its effect on fur-bearing populations, particularly our ecosystem engineers. 

The beaver was the most important animal to fur traders. Beaver were so critical to the industry that two different fur companies named their ships The Beaver. Why were beavers the cornerstone of the trade? Beaver fur could be shaved down into a sturdy, yet pliable felt for hats. Gentlemen, clergy, and military men all wore hats made out of beaver felt because it was the highest quality material. By the seventeenth century, Europe was running low on beavers and they were desperate to find a new source. When two explorers begged King Charles II for funding to explore the Hudson Bay which lay west of France’s colonial land. Charles sent them on an expedition and when they came back to England, they reported that beavers were everywhere. That was enough for Charles II who granted a royal charter, creating the Hudson Bay company in 1670. 

Fort Vancouver, Photo Credit: National Park Service

The Hudson Bay Company (HBC) was late to exploring the Pacific Northwest, but eventually they set up at Fort Vancouver, across the Columbia River from modern-day Portland. The move to the Pacific Northwest allowed the HBC to venture into regions like Central Idaho which were previously unreachable. Notable Hudson Bay fur traders arrived in the Sawtooths in the 1820s and 1830s and found the landscape to be treacherous. The mountains, the Salmon River, the indigenous people, and rival American fur traders made for difficult ventures. John Work, an HBC trapper, came into the Sawtooths via the South Fork of the Boise River in May of 1832. Work and his team noted that there were heavy snows and frozen beaver dams in the creeks even though it was May. The trappers didn’t linger long in the Sawtooths, leaving as soon as they found enough beaver pelts. In the early 1800s, a beaver pelt was worth around a gallon of whiskey and 4 pelts was worth a pistol. Some trappers called beavers “furry banknotes.” The high price for beaver pelts led to widespread overhunting.

The fur trade transformed North America but it nearly destroyed the population of several fur-bearers like muskrats and beavers who are critically important to their ecosystem. Beavers are the most notable ecosystem engineers. Sometimes, beaver engineering plans interfere with their human neighbors. A great example of this is when a beaver on Fishhook Creek kept building dams and flooding the Redfish Visitor Center parking lot. However, there are many times when humans desperately need beavers to fix the landscape. A rancher in Preston, Idaho wanted a small creek to provide water to his cattle all year long. He personally bought beavers and released them near the creek, but they never stayed. The rancher eventually reached out to Utah State University, which sent biologists to survey the creek. The biologists installed beaver dam analogs (fake beaver dams) that retained spring snowmelt to create deep water reservoirs. Once the beavers had deep water in the creek, they made their own dams and the creek immediately improved. Now, the small creek lasts longer in the dry months and wildlife such as fish and birds thrive in the improved ecosystem. 

Muskrats are ecosystem engineers just like beavers! They feed all year round and have been known to decimate vegetation, especially in wetland areas. One of a muskrat’s favorite snacks are cattails, which wetland biologists consider to be a menace. Not only are they non-native, but they grow rapidly stealing both the space and resources from native plants. This decline in native plants negatively impacts birds and others who feed on the vegetation and seeds. Cattails dominate an area and homogenous zones aren’t good for the overall health of an ecosystem. One Ecosphere study found that muskrats in the Thousand Islands region of the St. Lawrence River were the key to a healthy ecosystem. When biologists surveyed muskrat areas and compared them to non-muskrat areas of the St. Lawrence River, they found that muskrat areas had fewer cattails and higher native plant diversity, which positively impacts the birds, fish, and other residents. Muskrats’ impressive appetites are why scientists consider them to be ecosystem engineers.  

Fur trapping is a complex point in North American history. From one view, fur trapping is what brought French explorers to Canada and the American Midwest, and it gave indigenous people bargaining power with colonizers. However, from an environmental history perspective, the fur trapping industry nearly wiped out our most important ecosystem engineers. It is estimated that there were over 100 million beaver in North America before European settlement. By 1840, they were nearly extinct. The beaver population recovered thanks to efforts from conservationists who advocated trapping limits and reintroduction programs. Today, there are about 15 million beavers in North America and our ecosystems are better because of them. And we are lucky that our muskrats and beavers are not creatures of the distant past. 

Releasing beavers into the Salmon-Challis Forest, 1938 

Photo Credit: University of Idaho Digital Collections, SIHA Archive


Megan Nelson is the Docent at the Stanley Museum. She is passionate about the Sawtooths and its history. When she isn’t at the museum, you will find her at Redfish Lake or on a hike in the wilderness!


Bansal, S., Lishawa, S.C., Newman, S. et al. Typha (Cattail) Invasion in North American Wetlands: Biology, Regional Problems, Impacts, Ecosystem Services, and Management. Wetlands 39, 645–684 (2019). 

Gismondi, Melissa. “The Untold Story of the Hudson’s Bay Company.” Canadian Geographic, published May 2, 2020, last updated May 17, 2022. Accessed on July 23, 2023.

Elliott, T. C. “The Journal of John Work: July 5-September 15, 1826.” The Washington Historical Quarterly 6, no. 1 (1915): 26–49.

Kua, Z. X., Stella, J. C., and Farrell, J. M.. 2020. Local disturbance by muskrat, an ecosystem engineer, enhances plant diversity in regionally-altered wetlands. Ecosphere 11(10):e03256. 

Stuebner, Steve. “Restoring Beaver.” Life on the Range. Accessed July 27, 2023.

“Standard of Trade,” Hudson Bay Company History Foundation, accessed July 25, 2023.

Wandschneider, Rich. “How Much Was a Beaver Pelt Worth?” Josephy Library of Western History and Culture, April 16, 2021. Accessed on July 31, 2023.