It’s estimated that as many as 60 million bison roamed the grasslands and Great Plains of North America during the 19th century.

“This is the most magnificent mammal on our continent. Its story is so complicated and so interesting and moves into every aspect of almost every era of our lives and touches on so many subjects you wouldn’t think it would necessarily touch on,” says filmmaker Ken Burns of our national mammal, Bison bison. Burns is the producer of the new, two-part, four-hour series titled The American Buffalo, now streaming on the Public Broadcasting System (PBS).

After watching the series, I realized how intricately bison are woven into our national history, into our ideas of what America is and what it should be, and into the sometimes not-so-pretty tale of how we have, over the decades, lived with the natural world. All three of these concepts, I believe, have been carried inside the huge, beating chests and outside on the massive backs of these wild beings in their natural habitats.

That’s why the near extinction of the North American plains bison in the late 1800s caused a devastating loss to us as a whole nation. But beyond those big issues of history, national identity and our relationship with the natural world, what’s not quite as well-known are the ripple effects that the rapid loss of bison caused: lasting economic and physical shocks to the Indigenous peoples whose lives depended on the animals and the still-apparent ecological blow to our environment.


However, by 1870, it’s thought that only 8 million bison were left. Just 20 years later, fewer than 500 of the iconic animals remained.

Removing bison leaves lasting impacts on Indigenous peoples

The mass slaughter of North American bison by settlers of European descent is an infamous ecological disaster. An estimated 8 million bison roamed the United States in 1870; but just 20 years later, fewer than 500 of the iconic animals remained.

For more than 10,000 years, bison served as the primary source for the livelihoods of countless Native Americans in the Great Plains, Northwest and Rocky Mountains regions. Along with nutritional foods, the animals provided hides for blankets, clothing and lodging, as well as bones for making implements and tools. Nearly every part of the animal was used, including the brains to obtain grease for tanning hides and the stomach for creating bags and water containers. Evidence suggests that bison-reliant Indigenous societies enjoyed living standards comparable to—or, in some cases, better than—their European contemporaries.

However, the introduction of the horse and the arrival of Europeans began the gradual decline of bison populations. By 1870, mass slaughter of the animals started. The completion of the transcontinental railroad, improvements in European tanning technology that made bison hides more desirable and encouragement by the U.S. Army to eliminate the animals to help in their efforts to force Indigenous peoples onto reservations all drove the kill-off.

All Three Public Domain; Created by Candice Gaukel Andrews

Bison coats were in fashion during the great buffalo hunts of the 1860s to the 1880s. Such coats were also adopted by the U.S. Army for use on the frontier in the 1870s. Beaded, bison-hide gun cases, such as the one on the left, were also popular.

The mass slaughter provided a brief economic boon to some newly arriving settlers, hunters and traders of the Great Plains who sold bones and hides for industrial uses. In some areas, the bison was eliminated in a little more than a decade. It marked one of the largest and most rapid losses of a critical industry in North American history. Centuries of human capital were built around the use of the bison; but within 10 to 20 years, this economic underpinning vanished.

For Indigenous peoples, though, the loss of bison was nothing short of a devastating economic shock. They were forced onto reservations, their movements were restricted and they were not allowed to become citizens of the United States until 1924. A recent study, published in journal The Review of Economic Studies in May 2023, finds that those economic reverberations are still being felt in native communities today.

To quantify the impacts of the bison slaughter for that study, economists used data collected by anthropologists and published in the 15-volume, Smithsonian Institution’s Handbook of North American Indians. The economists defined 24 Indigenous nations as “exposed to the slaughter,” based on geographic location and whether bison served as their primary food source. In their quantitative analysis of bison-reliant nations with Indigenous nations that were not bison-reliant, they controlled for factors such as differences in the self-governance status of communities, differences in forms of agricultural productivity and the suitability of the land for agricultural production, the effects of the Dust Bowl and differential applications of the Dawes Act of 1887, which authorized the breakup of reservation land into small allotments parceled out for individual ownership. To measure the persistent effects of the bison’s decline on economic outcomes, the researchers drew from several sources: American Community Surveys (2007-2012 and 2015-2019), the Bureau of Indian Affairs (beginning in 1945) and the U.S. Census (1980, 1990, 2000).

Public Domain

The 1930s Dust Bowl on the Great Plains was one of the factors taken into account when studying how the presence of bison on a prairie causes flora to be more resilient in the face of climate extremes.

The economists’ results showed that income per capita remained 25% lower, on average, for bison-reliant nations compared to other nations through the latter half of the 20th century to today. That persistent gap could not be explained by differences in factors such as agricultural productivity, self-governance or application of the Dawes Act. And, in the early 20th century, the probability of a working-age male reporting an occupation was 19% lower compared with Indigenous nations that were never dependent on bison.

The researchers did find relatively more favorable trajectories for bison-reliant communities that were located nearer to financial institutions in 1870 when the mass slaughter of the bison began. Proximity to a bank and access to credit appeared to be one important factor to help alleviate some of the financial hardship generated by the bison decline. But many Indigenous communities are still located in “banking deserts.” That makes it more difficult for people to adjust to any kind of hardship.

I think one unexpected but striking example of the fallout from the loss of the bison was the change that occurred in the average height of bison-reliant people. Adult height across a population is one proxy of health and wealth, given that it can be impacted by disease and nutrition, particularly early in development.

Public Domain

Bison-reliant people suffered the most fallout from the near extinction of the animal in the late 19th century. Finally, in 2019, some Yellowstone National Park bison were repatriated onto the Ft. Peck Indian Reservation in Montana.

Bison-reliant Indigenous men stood about six feet tall on average, or about an inch taller than Indigenous men who were not bison-reliant. They were among the tallest people in the world in the mid-19th century. But after the rapid near extinction of the bison, the average height of people also quickly declined. Within one generation, the average height of Indigenous peoples most impacted by the slaughter dropped by more than an inch.

The study also shows that in the early 20th century, the child-mortality rate of bison-reliant Indigenous nations was 16% higher compared with Indigenous nations that were never dependent on bison.

The economists conclude by saying that one of their roles is to provide quantitative evidence that people can turn to when trying to design more effective policies. By providing data that benchmarks disparities among bison-reliant people and the sources and evolution of these disparities, they hope to support efforts to improve the situation.

Pixabay; Created by Candice Gaukel Andrews

A study more than 30 years in the making finds that reintroducing bison would double plant biodiversity in a tallgrass prairie.

Reintroducing bison increases diversity and drought resilience

Before they were abruptly removed from more than 99% of the Great Plains, bison were an integral part of North American grasslands. Since this great loss occurred before quantitative records were kept, the ecological effects of the removal of overwhelming numbers of bison were largely unknown.

So, Kansas State University researchers recently conducted a study in the Flint Hills tallgrass prairie ecosystem, one of the largest remaining tallgrass prairie landscapes. Using more than 30 years of data collected at the Konza Prairie Biological Station, they examined plant community composition and diversity under three different types of management treatments: 1) no megagrazers had been present; 2) bison were reintroduced and allowed to graze year-round; and 3) domestic cattle were introduced and allowed to graze during the growing season.

Results, published in the journal Proceedings of the National Academy of Sciences in August 2022, showed that reintroducing bison doubles plant diversity in a tallgrass prairie. In addition, plant communities with bison present had withstood the most extreme drought in four decades, consistent with the idea that diversity promotes ecological resilience. And this persistence will only become more important if our climate becomes even more extreme.


According to the National Park Service, the selective grazing of bison results in a heterogeneous plant landscape. By feeding mostly on grass species and consuming woody vegetation only when food is limited, they create a spatial, mosaic pattern of grazed and ungrazed areas that promotes plant diversity.

These gains are now among the largest recorded increases in species richness because of bison grazing in grasslands, say the researchers.

The Kansas State University study also demonstrated that cattle had a positive impact on plant diversity, compared to having no large grazers present, although increases in plant species richness were significantly smaller than those caused by bison. That’s because many of those in cattle production conduct prescribed fires that keep grasslands from becoming woodlands. So, when it’s economically and ecologically feasible, reintroducing bison would have the most positive effect on biodiversity conservation.

On a sadder note, however, these results suggest that many grasslands in the Great Plains have substantially lower plant biodiversity than would have occurred if the bison hadn’t been widely wiped out. The best hope now would be to return or rewild native megafauna to help restore grassland biodiversity.

NatHab Images

American bison are currently listed as “near threatened” on the IUCN Red List of Threatened Species and need to be returned to their natural habitats. World Wildlife Fund partners with Native communities—such as the Fort Belknap Indian Community, the Fort Peck Assiniboine and Sioux Tribes, and the Sicangu Lakota Nation—that seek to restore bison to their lands. WWF also works with the U.S. National Park Service and Parks Canada on bison restoration efforts. ©Colby J. Brokvist

Remediating the loss of bison heals our nation—and the nations within it

Bison-reliant nations have been connected to this wild animal since time immemorial. For the people of those nations, bison were not only seen as a food source and the providers of material goods, but as kin—and not in just a metaphorical or symbolic kind of way. They were real relatives. Ripping them away from their families in such a brutal manner, I think, is something that we still need to reckon with.

Bringing and welcoming back bison brothers to their natural habitats is a start.

Here’s to finding your true places and natural habitats,