The Henry Mountains of southeast Utah are famous for being the last mountain range in the contiguous United States to have been officially mapped. Indeed, before they were mapped, they were often referred to as the “Unknown Mountains.” Another relative unknown detail about this range is that it harbors one of only five genetically pure, free-roaming bison herds on North American public lands.
In 1941, a seed herd of 18 American Plains Bison (B. b. bison) were transplanted from Yellowstone National Park to the arid desert of Utah’s Robbers Roost. A year later, five more bulls were introduced to the herd in hopes of sufficiently diversifying the gene pool and sustaining the herd. The bison must not have found Robbers Roost as appealing as Butch Cassidy had, though, because this new Wild Bunch set out for literal greener pastures that very same year.
The small herd forded the Dirty Devil River and traveled southwest toward the Burr Desert. The herd stopped here for a while, enjoying their newfound buffet atop the Aquarius Plateau. 21 years later, though, in 1963, the still small herd grew tired of the desert and abandoned it altogether for the higher, more verdant snow-fed meadows of the nearby Henry Mountains. Here, the herd thrived and quickly swelled in numbers.
Today, the herd’s population is estimated to be between 300 and 400 animals, which ecologists and wildlife biologists regard as the maximum carrying capacity of their Henry Mountain range. The Utah Division of Wildlife Resources has responded accordingly. In an effort to perpetuate the health of the herd and their range, the DWR began issuing “Once-in-a-lifetime” permits to hunters hoping to fulfill not only a tag but also a burning sense of adventure. The Henry Mountains, after all, were mapped last for a reason. They remain one of the most rugged and remote places in a state known for its rugged and remote places.
Fittingly, quite unlike their more quintessential Plains Bison brethren, the Henry Mountains bison can be found almost anywhere in the Henrys between the desert lowlands and timberline. Apparently, no one has told the herd that Plains Bison doesn’t typically like high elevations or steep mountain slopes. This unique proclivity of the Henry Mountains herd to cast off behavioral stereotypes works in their favor when hunting season rolls around and they abandon the high, open meadows for steep, wooded canyons and thick groves of aspen and evergreens.
This highly adaptive nature unique to the Henry Mountains herd made it an obvious candidate to serve as a seed population in early 2010 when 39 individuals were transplanted from the Henry Mountains to the Book Cliffs along the Utah-Colorado border. These 39 animals were to serve as a genetic supplement to a relatively new herd first reintroduced to the Book Cliffs by the Ute Indian Tribe in 1986. The now 600-strong Book Cliffs herd is well on its way to reestablishing the American Plains Bison’s historic range in the Book Cliffs.
The story of the Book Cliffs and Henry Mountains Bison give us reason to hope that one day soon, the American Bison might reclaim its territory, a historic range that once ran from Alaska through the Canadian territories and the Great Plains to the Eastern Seaboard and the Gulf of Mexico. And, if so, the role the Henry Mountains herd will play in that expansion may be a significant one.