Less than three hundred years ago, bison roamed a huge swath of the North American continent, from Mexico up through Canada, and from nearly the east coast of the United States through the American West.

The animals were a livelihood for many of the people who lived in the region, providing food, shelter, clothing and other means of survival.

Then came white settlers, who destroyed the animals’ habitat and hunted them by hundreds of thousands, sometimes leaving their carcasses to rot. By the late 1800s, the animals were all but wiped off the continent.

The historical record shows the bison’s disappearance had immediate effects on the health and wellbeing of tribes that depended on them.

But the effects weren’t only immediate, says a working paper published by the Federal Reserve Bank of Minneapolis’ Center for Indian Country Development: More than a century after the American bison nearly went extinct, the tribes that relied on them still have lower incomes, and higher rates of suicide mortality and unrest than those that didn’t.

Healthy and wealthy

Some indigenous tribes in North America developed a symbiotic relationship with the bison. They cleared forests and grew grasses that give the animals a habitat. In return, the bison provided them with food, which could be kept over time, shelter, in the form of tipi covers, clothes and fire, among other tools for daily life. At one time, there were as many as 60 million bison in North America.

Bison-reliant Native Americans had among the highest standards of living in the world at the time. Because they don’t have economic data on indigenous societies going back in time, researchers use height as a proxy for wellbeing. According to a sample collected by an anthropologist in the 1890s, members of the Plains tribes — many of whom hunted bison — stood taller, on average, than Americans or Europeans. Men from the plains tribes averaged 173 centimeters, or 5 feet 8 inches tall, compared to 172 centimeters for the average Australian man, 171 centimeters for the average American man of European descent and less than 170 centimeters for the average European man.

“Due in part to the plentiful nature of the bison and the ability to store its food products for years [by drying it], the bison peoples were arguably the wealthiest people in North America and at least as well off as their average European counterparts,” the paper’s authors write.

Donna Feir, a Center for Indian Country Development research economist, became interested in quantifying the effects of the bison’s extinction when she saw a gap in research: while people had studied why the bison disappeared, they hadn’t quantified the long-term effects on tribes.

“The absence of economic literature around the consequences of the loss of the bison has always been a bit perplexing,” Feir said. Especially since some of the indigenous people who most acutely felt the loss of bison still seem to be paying for that loss.

“How did some of the wealthiest people on the continent — maybe in the world — how did they become some of the poorest people in North America today?” Feir asked.

A devastating loss

By the late 1800s, the American bison was nearly extinct, numbering less than 350 on the North American continent.

In order to quantify the effects of the loss of those animals, Feir and her team separated bison-reliant tribes from non-bison reliant tribes, then divided bison-reliant tribes into two groups: those that lost the bison slowly over the course of about a century, through hunting, competition with settlers’ cattle and displacement; and those that lost the bison quickly: when new technology made tanning rough bison hides efficient enough to make their sale economically viable in Europe, their population was decimated as they were hunted for warm furs.  The U.S. government also killed bison, in some cases, to control Native Americans who resisted moving off lands.

To define the difference, researchers overlaid maps of where tribes lived before they were moved to reservations with a century-plus-old map created by William Temple Hornaday, then the chief taxidermist for United States National Museum at the Smithsonian Institution, that chronicled the loss of the American bison. The animals disappeared from parts of the east as early as the 1720s and 1730s. Going west, they were all but gone from most of the continent by the 1870s, with only small populations left into the 1880s.

The loss of bison was devastating to tribes that depended on the animal, but moreso to the tribes for whom the bison disappeared quickly, the researchers found.

Today, reservations made up of bison-reliant tribes for whom the animal disappeared slowly have about $1,600 lower per-capita income than non-bison-reliant tribes. Tribes that lost the bison quickly have per-capita income of about $3,800 less than non-bison-reliant tribes.

Societies that lost the bison shrunk in height by between 2 and 4 inches, with greater losses among tribes that lost the bison quickly, according to the paper.

The researchers adjusted for factors such as time of contact, the introduction of the railroad and soil quality, and still found that bison-reliant societies that lost the bison quickly are worse off today than those who lost the bison slowly. Both did worse than  those who were not dependent on the animal.

Federal policies made it difficult for members of indigenous tribes to move off their land, and in many cases, made farming the only way to make a living. Because of that, tribes that had a history of farming, even if they were bison-reliant, initially suffered because of the loss of the bison, but saw near-recovery by 2000.

But the effects aren’t just economic. Feir and her colleagues also found higher rates of suicide mortality and conflict today in tribes that depended on bison for sustenance more than a hundred years ago.

“The loss of the North American bison was arguably one of the largest economic shocks in history,” Feir said.