November marks 30 years since The Nature Conservancy bought and started maintaining the Joseph H. Williams Tallgrass Prairie Preserve in Osage County.
For the past 26 years, the bison have gone through a roundup, where they are given vaccinations and weighed. Several hundred of them are then sold each year.
The moments just before the roundup are calm. Then, things get dramatic, as the bison run across the prairie and do their best to avoid their annual health check-up.
After about one minute of getting looked over and receiving any shots they need, the bison are released.
"They're pretty hardy animals. They don't need much care,” Nature Conservancy Community Relations Coordinator Harvey Payne said.
Payne has been at the prairie for all 26 roundups over the years.
"It never gets old,” Payne said.
2019 also marks a milestone for The Nature Conservancy, which purchased the prairie 30 years ago.
"This seemed like the impossible dream. The National Parks Service wanted a prairie park since the 1930s. All of those earlier efforts failed. And for the conservancy to come in and do this in 1989 was monumental,” Payne said.
The preserve includes the largest protected section of tallgrass prairie left in the world. Taking care of it means taking care of the bison - and managing a healthy number of them around.
Right now there are roughly 2,500 on the land. About 600 calves were just born in the spring, and now they're going through their first roundup. For about 600 grown bison, this will be their last before they're sold.
"That's one of the bigger reasons we do roundup is to adjust the stocking rate each year,” Tallgrass Prairie Preserve Director Bob Hamilton said.
Hamilton leads a team of cowboys during the roundup.
"Being around such a classic, iconic species as the American bison, it's just a blessing,” Hamilton said.
As they work on the bison one at a time, Hamilton said the 30-year anniversary causes him to reflect.
"We're really just getting going,” he said.
He said the goals going forward include working with nearby landowners on the conservancy’s mission of conservation.
The roundup is expected to wrap up early next week. It is not open for public viewing.