On 39,100 acres just north of Pawhuska, Okla., conservationists are trying to recreate the unique environment of the presettlement tallgrass prairie. Though this vast ecosystem once covered more than 142 million acres, it is almost entirely gone today. Most of it was long ago transformed into farmland or forest.
But the Nature Conservancy, a national charitable organization dedicated to preserving natural landscapes, seeks to protect this patch of prairie in Osage County by bringing back two of the Great Plains’ most significant natural forces: fire and the American bison.
Spring visitors to the Tallgrass Prairie Preserve will likely encounter both of these things. Groups of bison are frequently found grazing beside public access roads; smoke or scorched earth marks ongoing or recent burns.
According to Robert Hamilton, director of the Tallgrass Prairie Preserve, bison were the “premier influence” of the presettlement plains, “a force of nature in themselves.”
Together with fire and the impact of Native Americans, bison created the ecology of the prairie. The historical tallgrass prairie region was a chaotic place where the human use and natural outbreak of fire drove the movements of grazing mammals, who were preyed upon by human and non-human predators alike.
In the wealth and diversity of the Great Plains, Hamilton said, “we had the original Serengeti.”
But unlike their ancestors, the bison of Osage County must content themselves with the rolling landscape of Oklahoma’s Flint Hills. The age of the buffalo is long over.
Before 1800 there were probably 28–30 million bison on the Great Plains. By 1900 there were fewer than 1,000.
A combination of exotic bovine disease, global demand for bison robes, and increasing pressures from displaced and adapting Plains Indians had led already to a decrease in the bison population by 1850, according to Dan Flores, author of “The Natural West.”
But it took two great periods of slaughter at the hands of mostly white hunters in the 1870s and 1880s to fully humble the American bison.
The bison had all but vanished by the time William T. Hornaday, then superintendent of the Smithsonian’s National Zoological Park, wrote his polemical 1889 treatise on the “Extermination of the American Bison.”
As Hornaday and others reported, it was common practice among bison hunters to kill an animal solely for its robe or its tongue. Many hunters rarely paused to strip the meat from their kill, and most of them killed far more animals than they could actually make use of.
Frank Roe, who appears to have mustered every available source for his encyclopedic 1951 study “The North American Buffalo,” wrote that every bison robe brought to market in the years 1871 and 1872 represented anywhere from three to five dead buffalo.
Oklahoma was not spared the carnage. White hunters were not then allowed to ply their trade in Indian Territory (as most of present-day Oklahoma was known); this was little impediment to the determined hide hunters.
Hornaday reported that such men would camp out on the south Kansas border to lie in wait. “A herd no sooner crossed the line going north than it was destroyed,” he wrote.
In preparing his work, Hornaday tried to establish the number of bison still alive as of Jan. 1, 1889. The very scarceness of the animal in question seems to have made his job easier:
“In the United States the death of a buffalo is now  such an event that it is immediately chronicled by the Associated Press and telegraphed all over the country.”
According to Hornaday’s numbers, there were only 635 wild bison in North America at the beginning of 1889: 25 in the Texas panhandle, 20 in Colorado, 26 in southern Wyoming, 10 in Montana, 4 in the Dakota territory and perhaps 550 in Canada’s Northwest Territory.
Together with captive animals, including those protected by federal law in Yellowstone, he put the total number of living bison at 1,091.
More than twice that number now live within the confines of the Tallgrass Prairie Preserve. In 1993, the Preserve received a donation of 300 animals from the Ken-Ada Ranch in Bartlesville. Since then, the herd has grown to a summer size of 2700. Most of that growth was through natural reproduction.
Free to wander throughout most of the Preserve, these bison are essentially wild. The Nature Conservancy gathers them only once a year to administer vaccines and remove excess animals. Without external predation, the herd’s natural birth rate exceeds its mortality rate, so a little intervention is necessary to keep the herd at its target size.
Otherwise, the herd is left to its own devices.
But the herd is only the first step in recreating and preserving this tallgrass prairie ecosystem. The plains are notorious for their vast open, but seemingly empty vistas. In spite of this reputation for dullness, the prairie is a complex and delicate system.
“The problem with grassland conservation is that the prairie isn’t the sort of jaw-dropping, hit-you-in-the-face scenery of the Rocky Mountains or Himalayas,” Hamilton said. Instead, the prairie is a subtle, but complicated machine with many hidden, moving parts. “It’s like the inside of a clock.”
And like a clock, all the parts need to be properly balanced and aligned.
“For the prairie to work, it needs three things,” said Bill Alexander, a volunteer docent at the Preserve: “the climate, the fires and the bison.”
The bison fertilize and aerate the soil, Alexander said. As they pursue the best grazing, these benefits spread to diverse parts of the landscape. But bison alone will not preserve the prairie.
“If you remove fire,” Hamilton said, “it quickly becomes woodland.” Besides paving the way for lush, new growth, fire protects the prairie, shielding it from the onslaught of its forest neighbors.
The transition from prairie to woodland can happen in the span of a human generation, according to Hamilton. “As a land manager, you’ve got to move fast and not sit on your thumbs,” he said.
So the second weapon in the Tallgrass Prairie Preserve arsenal is the controlled burn. Every year, the Preserve burns a full third of its holdings, choosing sections spread throughout its 39,100 acres.
The result is a “shifting landscape patch mosaic,” in Hamilton’s words. This mixture of burnt and unburnt patches is critical to the Nature Conservancy’s mission at the Preserve. “You need to have this landscape diversity out there,” Hamilton said, “if you want all the native species to survive.”
A man-made landscape
The Preserve has been a hotspot for biological, ecological and environmental research. Over 180 papers have been published on the basis of research conducted at the Preserve.
Scientists working at the prairie have access to a research station at the preserve headquarters. Built by the Nature Conservancy in partnership with the University of Tulsa, the Tallgrass Prairie Ecological Research Station was dedicated in 2004.
Dr. Kerry Sublette, Sarkeys Professor of Environmental Engineering at TU, has been involved with the research center since the fundraising process began four or five years before. Sublette has been conducting oilfield remediation and restoration research at the Preserve for over twenty years.
With around 200 active oil wells, the Tallgrass Prairie Preserve is not without its mishaps. But for Hamilton, the Preserve shows that oil and gas production is compatible with conservation.
It still helps to have Sublette around, though. “I think of Kerry and his team as the Ghostbuster guys,” Hamilton said. That is, when something spills in your neighborhood …
The Preserve’s land management plan also serves a research purpose.
Patch-burning as practiced at the Preserve differs from more conventional practices, some of which involve burning all pasturage every year. 11,000 acres of the Preserve are set aside for the testing of progressive land management techniques with domestic livestock like cattle.
The active role played by the Nature Conservancy in maintaining landscape diversity clashes with what Hamilton calls the “keep the chainsaws out of the forest, human beings aren’t part of nature” approach to conservation. Hamilton thinks this view ignores the substantial role played by Native Americans in managing the prairie before the extermination of the bison.
The prairie is in some ways a human-created environment. “Without people, we would not be talking about a prairie system,” Hamilton said. For thousands of years before 1800, indigenous people were already using fire on the prairie, both to drive animals off cliffs or into corrals and to lure them with vibrant new growth.
But instead of lighting fires for the sake of food, the Nature Conservancy does so to protect the tallgrass prairie from extinction.
At a prescribed burn last Saturday, a team of three Oklahoma State University researchers lead by Joe Lautenbach were conducting a raptor survey. Standing in the back of a pickup truck, one would say the name of a bird and another would write it down. “Turkey Vulture.” “Swainson’s Hawk.”
By early afternoon, the prairie smoldered on the east side of the road leading south out of the Preserve. On the other side, a bison lay calmly on a verdant patch of ground which had burned only weeks before.