Wyoming’s wild bison are the first of the ungulates (hooved animals) to kick off the fall breeding season, or rut.
For bison, the rut starts in July, but really gets going in August and carries into September. At some 2,000 pounds, bull bison are the largest land mammals in North America.
Watching these rutting behemoths battle each other, roll in the dust and incessantly chase the cows is truly an impressive sight. One might think the bison of Yellowstone and Jackson Hole are one big herd, but they’re not.
A portion of the Jackson bison herd graze beneath the backdrop of the jagged Teton Range at Elk Ranch Flats in Grand Teton National Park recently. (Mark Gocke/WyoFile)
They are two distinct herds, with little interchange between them. The history of the Jackson Bison Herd is an interesting one.
Bison were native to all of Wyoming and several surrounding states, once numbering in the hundreds of millions. The decimation of bison across their expansive range throughout the 1800s has been well documented, and by the mid 1880s they were extirpated outside Yellowstone National Park.
A rutting buck pronghorn herds his harem of does on Antelope Flats in Grand Teton National Park. (Mark Gocke/WyoFile)
Jackson Hole wouldn’t see bison again until 1948 when 20 animals were brought to a fenced enclosure called the Jackson Hole Wildlife Park west of Moran Junction, near what is known today as Oxbow Bend in Grand Teton National Park. The wildlife park was also a place for visitors to see elk, moose, deer and pronghorn antelope.
A rutting bull bison nudges a cow to see if she’s receptive for mating in GTNP recently. (Mark Gocke/WyoFile)
The breeding season for elk, moose and pronghorn typically begins in early to mid-September and runs through October. Deer generally start in November and bighorn sheep begin in late November into December.
It is reported that the bison would regularly escape their pen each year and have to be rounded up. In 1969, park officials decided to stop trying to round up the escapees and thus began the modern day free-ranging wild bison herd in Jackson Hole.
In 1975, it is reported that the bison discovered the National Elk Refuge at the southern end of the Jackson Hole valley, near the town of Jackson. Soon after, they would also find the supplemental winter feed that had been doled out for the free-roaming elk herd since the creation of the refuge in 1912.
Absent normal winter mortality, the bison population began to grow at a rapid rate. By the mid-1990s, the Jackson bison herd was approaching 1,000 animals. Bison were showing up on horse and cattle feed lines on private lands, sometimes goring livestock. Bison were also regularly having to be herded off the green grass of Jackson Hole golf courses and residences along the Snake River and in the town of Kelly. Bison numbers needed to be controlled.
As with all of Wyoming’s big game, recreational hunting was the desired tool of wildlife managers for curbing growth. And there was no shortage of hunters ready and willing to help bring numbers down.
A rutting bull bison gets up and shakes after wallowing in the dirt in Grand Teton National Park recently. (Mark Gocke/WyoFile)
However, through legal action, the Fund for Animals successfully blocked bison hunting on the National Elk Refuge until an interagency management plan was approved in 2007, which allowed for hunting on the refuge. By this time the bison herd had hit 1,200 animals.
Over the next several years, hunters would help managers bring the population back down to the desired population objective of 500, which is where it hovers today. Still, Wyoming is one of only a handful of places in the world with a wild, free-ranging bison herd for all to enjoy.