Montana's bison lawsuits seems to ignore the National Park Service's outreach/NPS file, Jacob W. Frank

A lawsuit Montana filed against the Interior Department, National Park Service Director Chuck Sams, and Yellowstone National Park Superintendent Cam Sholly claims the Park Service long has ignored Montana's concerns over free-roaming bison, but park correspondence says otherwise.

Indeed, a three-page letter (attached below) Sholly sent Gov. Greg Gianforte last summer states that in 2021 the park superintendent invited Montana officials to offer their own alternative for inclusion in the Bison Management Plan that was under development at the time.

"You've had multiple visits from me, senior DOI leadership, and Yellowstone's wildlife team, at your request. Over two years ago, I offered to consider and include a State alternative in the analysis," Sholly wrote last July. "That offer was never followed up on." 

As we pointed out last week, managing Yellowstone bison long has been a controversial issue due to concerns they could spread brucellosis to cattle herds in Montana.

Brucella abortus, a bacterium thought to have reached the country from European livestock, can cause spontaneous abortions or stillbirths in bison and cattle. Until 2010, if two or more herds in a state contracted the disease, or if a single herd detected to carry the disease was not sent to slaughter, all herds in that state were blacklisted from markets. Today that blacklisting applies only to the affected herd. Nevertheless, the risks of the disease infecting cattle have stigmatized Yellowstone bison and impacted their instincts to head outside the park for calving and prevented the spread of their genes to other bison herds in the West.

Worries over the spread of brucellosis by bison led to adoption of the Interagency Bison Management Plan (IBMP) in 2000 after Montana sued the federal government five years earlier over brucellosis fears. However, research conducted in 2016 concluded that elk, not bison, infected cattle herds in Montana and, overall, posed a greater threat than bison to spreading the disease in the region.

“In tracing the genetic lineage of Brucella across the ecosystem and among species, elk are now recognized as a primary host for brucellosis and have been the major transmitter of B. abortus to cattle,” the National Academies of Sciences concluded in a paper published in 2017. “All recent cases of brucellosis in [the Greater Yellowstone Area] cattle are traceable genetically and epidemiologically to transmission from elk, not bison.”

Nevertheless, Montana takes a much harsher view of bison entering the state than it does elk. Indeed, in the introduction to the lawsuit the state's attorneys charged that Yellowstone's "bison population boomed, spilling brucellosis-infected bison into Montana and forcing the State to pick up [Yellowstone National Park's] slack in order to protect its livestock industry from the disease."

Elk, however, are viewed as cash cows by the state. In compiling its 2023 Elk Management Plan, Montana estimated that elk hunters generate more than $187 million a year for the state. Between 2004 and 2022, bison hunts in the state generated $2 million in license and tag revenues for the state.

While the state's lawsuit claims the IBMP adopted in 2000 called for a cap of 3,000 bison in the park's herds, Sholly said that would be unrealistic as it would "require aggressive removals of bison migrating to the park boundary, as well as in the park's interior. These actions could substantially decrease genetic diversity and skew the age and sex composition of the population. Low numbers of bison could lessen the long-term viability of the population and diminish the ecological role of bison at engineering habitats, redistributing nutrients, altering plant growth patterns, improving biodiversity, and providing meat for predators, scavengers, and decomposers. Most tribal hunting opportunities would also be eliminated."

What happens with the arrival of the Trump administration remains to be seen, but Dan Wenk, Sholly's predecessor at Yellowstone, felt he was pushed out during the first Trump presidency over a dispute with Montana officials over bison numbers. While then-Interior Secretary Ryan Zinke wanted the bison herd held to 3,000 individuals, Wenk was of the opinion a 4,000-head herd was sustainable.

The plan adopted by the Park Service last year calls for an annual population ranging from 3,500-6,000 animals.