Imagine a continent full of bison… and you have caught a glimpse into North America over 300 years ago, when there were approximately 50 million of them. From the Florida Everglades to the desert southwest to the plains of the Midwest, and the freezing Canadian Rockies. You could look across the landscape from your front porch and see more bison than any other animal.
I have been going to school at Montana State University in Bozeman, Montana for a year now, and decided to take the WRFI Conservation Across Boundaries course to explore the area more and learn how to integrate conservation and sustainability into my mechanical engineering degree. I learned about the immensity of historical bison populations while sitting on the shore of an isolated alpine lake in the Greater Yellowstone Ecosystem (GYE). The reality check that soon followed is that the North American bison population dwindled to less than 400 by the year 1900 due to over-hunting by European settlers and colonizers. Unfortunately, these bison were killed not only for their hides, but also due to policies which encouraged sport killing at incredibly high numbers to deplete an integral source of food for Indigenous people. I learned about the Lacey Act of 1900, a conservation law that makes illegal acts such as poaching or hunting in the park a federal offense. This act created protection for bison in Yellowstone National Park (YNP), and has allowed these bison to current day population between 3000 and 5000.
Indigenous communities have worked hard to return bison to their sovereign nations, and there is now a system in place to allow this to happen safely. Bison are an extremely strong part of many Indigenous peoples’ identity and spirituality, and some would say that even though returning them to their sovereign nations is an improvement, free roaming bison is the ultimate goal for their people. However, this process is very slow, not only due to administrative and legal hurdles, but because many of the bison in YNP are infected with a disease called brucellosis. This disease has minimal effects on bison, but causes infertility and early abortions in cattle. Additionally, it is easily transmitted via bodily fluids, for example nose-to-nose contact. Brucellosis is difficult to identify in bison because it can take up to six months for a bison to test positive, and there are no visible effects in the interim.
Brucellosis and other diseases in cattle is something I have experienced firsthand having helped my dad vaccinate young cattle in the blazing summer heat. He is a rancher, and I’ve learned from him how easily a disease like brucellosis spreads, as well as the drastic consequences it would have on an entire cattle herd, and in turn the rancher. Brucellosis would not only decrease the amount of babies (or calves) born that year, but would also require an extended period of quarantine for all cattle and expensive testing and medical attention. A disease like this infecting a cattle herd could easily put a rancher out of business and in a lot of debt. There have been no recorded brucellosis outbreaks in cattle since 2000, and no recorded interactions of bison intermingling with cattle since 2013. Although there are no documented cases of bison transferring brucellosis to cattle, the threat looms large in the minds of ranchers, as it has been proven to spread easily in a lab.
There is a vaccine given to cattle for brucellosis, but it is not extremely effective nor fully protective (like any vaccine), and is an added expense for ranchers. Another issue with the vaccine is that the bison are not vaccinated, which is something that could happen, but many are against because they want the bison to stay wild and have minimal human contact or intervention. Elk also carry brucellosis, but the abundance and lack of ability to contain the species means that the opinions and reactions regarding the control and containment of the disease from elk isn’t nearly as strong or political. That being said, I have been told of multiple instances of cattle getting brucellosis transmitted by elk from the other ranchers my dad does business with.
The conservation of bison is important to Indigenous populations and the visitors of conservation areas like YNP or the Black Hills in South Dakota, where I once witnessed a similar herd towering above me on the side of the road next to my car. Bison management in and outside of YNP remains a contentious issue. Stakeholders, such as tourists, private landowners, Indigenous communities, and hunters hold varying opinions about bison protection and freedom. Opinions range from bison being completely free and protected everywhere to having heavily controlled populations only in the park. This is a complicated and politicized issue not just because of the brucellosis, but also because of the large amount of private land outside the park and around the country, as well as the physical barriers humans have created across the landscape, most notably roads and fences.
My fellow students and I have spent time in the Snowcrest and Tobacco Root Mountain Ranges, both of which are a part of the GYE. This area spans the states of Wyoming, Montana, and Idaho and encompasses around 17 million acres (estimates vary depending on studies and ecosystem descriptions). This fractured landscape is a mix of private land, Bureau of Land Management (BLM) land, National Forest, wilderness areas, cities, and other jurisdictions under varying management systems. This region was once heavily populated with bison, but is now inhabited by cattle and wild ungulates (hoofed mammals). Much of the valley and grassland we have encountered on our bumpy van rides has been private land lined with fences and cattle. In the mountains we found mostly public land, also with fences and cattle (or signs of cattle). Much of this public land is leased to private ranchers who use it for cattle grazing. As we attempted to swiftly hike out of the Tobacco Roots to avoid a thunderstorm, we saw cattle that may have been the culprit of the cow pies we found on the shore of a breath-taking alpine lake at 9000 feet. This area used to be bison habitat, and could support them once again, but fencing and roads would prove to be significant barriers, in addition to the grazing land that they would compete for with cattle. These boundaries are cultural as well, creating many “winners and losers” depending on each decision, none of which will be accepted and liked by all stakeholders. For example, free roaming bison would be a win from the perspective of some Indigenous communities, but a loss according to many private landowners and ranchers.
Our class recently worked on a demolition fencing project near Butte, Montana that replaced an old sheep fence with a new wildlife friendly fence that pronghorn can go under because they can’t jump over fences. This is an example of conservation across boundaries, but there is currently no effective fencing equivalent for bison, for two main reasons. The first of which is that bison require much stronger, taller, and often electric fences, otherwise they will often just walk through and ignore them. Fences which can effectively keep out bison require more resources to build and maintain. Additionally, double fences are necessary to stop nose-to-nose contact and the spread of brucellosis from bison to cattle, furthering the extent of human boundaries required to manage bison. The economic and political strife between the different stakeholders of the GYE would make bison inhabiting these areas challenging, especially when trying to expand their regions and potentially even connect populations, but I believe it could be done.
The Yellowstone bison’s regions have been expanded to over 75,000 acres of conserved and managed land outside Yellowstone, but it has been a slow and meticulous process requiring cooperation between all stakeholders. Continuing to transplant brucellosis-free bison while solving the issues of increasing their range without negatively impacting land owners is the key to improving the lives of individual stakeholders, Indigenous people, the bison, and the GYE as a whole. As I stand in the Tobacco Roots overlooking a valley and hills full of prime grazing habitat, I wonder if there could ever be an economically effective way for a stable brucellosis-free bison population to share these tasty grasses with ranchers and their cattle.