Photo credit: Tom Olson.
Partner Organisation: Olson Bison Rewilding Project
Location: Canada
Step into the vast plans of Manitoba and Alberta, as we warmly welcome the Olson Bison Rewilding Project to our Alliance! With over 5,000 Bison roaming freely across areas in Alberta and Manitoba, the Olson family have quietly grown this passionate project into one of the most significant family-led rewilding efforts in North America.
This is a story about reviving the land, establishing cultural relationships, and setting new standards for what privately led conservation can achieve – one that began in 1992, when Tom Olson, an International Tax Lawyer, and his family set out to rewild Bison on the Canadian Prairies. Over the past three decades, he and his family have successfully rewilded bison across two extraordinary landscapes.
The first is Manitoba Bison Park, located in Pine River, Manitoba, an expansive 100,000 acre landscape of Tall Grass Parkland and Northern Fescue Prairie where over 5,000 wild-type Bison roam (referring to Bison that retain the original genetic, behavioural, and physical characteristics of their ancestors prior to extensive human interference). Here, Bison coexist among Moose, Elk, white-tailed Deer, a robust population of Wolves, Black Bears, and Lynx.
The second site is Waterton Bison Park, bordering Waterton Lakes National Park and Castle Wildland Provincial Park in Alberta, on the slopes of Spread Eagle Mountain. Though smaller at around 2,200 acres, it is a critical wildlife corridor between protected areas with Grizzly Bears, Black Bears, Wolves, Mountain Lions, Lynx, Moose, Elk, Mountain Sheep, Mule Deer, and white-tailed Deer roaming throughout.
Photo credit: Tom Olson.
Rewilding Challenges
Rewilding has not been without its challenges. Both parks have been pieced together from ranches and farms. The ranches, when first acquired, were heavily overgrazed and had significant populations of invasive species including, agronomic grasses. Many native plant species were unhealthy or even extirpated. In Manitoba, the boreal forest has expanded dramatically, overtaking most of the native prairie. At one point, forest cover had surged from an estimated 25% of landscape cover to 80%. In Alberta, the aspen forest has expanded from an estimated 20% of landscape cover to over 50%. The lack of large bison herds disturbing and limiting encroaching forests led to a loss of historic and critical prairie habitat for the large mammals that had historically occupied the parks.
A Living Laboratory
What sets the Olsons’ project apart is its rewilding philosophy. The Olsons rely on continuous observation, learning directly from how the land responds.
They are not here to control the land, they are listening to it. What they are witnessing goes beyond conventional science: Bison are not just part of the ecosystem, they are the key to rewilding the ecosystem. This starts with preserving their natural social structure rather than managing the Bison’s behaviour. They allow the Bison to act as ecological engineers. Bison roamed the Canadian Prairies in huge populations in balance with the First Nations, just as they have done for thousands of years – estimates say that in 1800 there were up to 30 million Bison on the Great Plains.
Their return is essential. The Olsons believe that without Bison, large-scale rewilding of most of the historic prairie and parkland of North America simply isn’t possible. Their grazing, movement, and disturbance are the driving forces that regenerate prairies, build soil health, store carbon, and sustain biodiversity. Rewilding at scale depends on them. The Olsons believe the following principles of bison rewilding:
- Large herds grazing intensively, create perturbation that sparks renewal, mimicking natural cycles that shaped the prairies for millennia;
- Migratory grazing promotes deep-rooted native grasses, storing carbon, holding and accessing water, and stabilizing soil, animating the carbon cycle with limited fire and no fertilizers or pesticides;
- Bison perturbation heals the ecosystem by promoting greater biodiversity among flora and fauna;
- As the Bison herd migrates, a tsunami of biodiversity follows in the path of bison perturbation; insects, birds, predators and even seeds of grasses, sedges and forbs that follow the migrating bison;
- As the historic native prairie plants are restored on scale, the biodiverse landscape becomes far more capable of enduring major climate events and even adapting to climate change. To be clear, bison is the only megafauna that has survived from the ice age so it is well suited to continue to adapt to changing climate;
- As the ecosystem heals under the hooves of Bison, predators that help reduce populations of biting flies and other harmful insects that are a scourge to large mammals become more abundant;
- Bison help disperse native seeds through their fur, hooves, and dung therefore promoting native plant recovery.
- Bison have a diverse diet including grasses, sedges, forbs and a noticeable part includes browsing willows, shrubs and sapling trees.
Fencing is used thoughtfully, not to confine, but to simulate migration patterns. This avoids continuous grazing and allows for long rest periods across the land. Intense grazing events are welcomed – historic Bison herds once moved through with great force and didn’t return, sometimes for multiple seasons. The Olsons believe that it is this cycle of disturbance and recovery that helps regenerate native prairie on the landscapes in which the Bison parks exist.
The Bison have had a significant effect on opening the canopy of the encroaching forest. Bison debark trees with their horns, killing the trees. When trees die, blow over, or burn, the bison prevent the saplings from filling the void through trampling and browsing. As sunlight penetrates the newly created small clearing, grasses, forbs and even shrubs that are found on the periphery of the forest, such as saskatoon berries and raspberries, emerge. The dead trees provide a great habitat for many insects and birds. These small clearings invite more bison activity in the forest with even more perturbation. Over time these clearings grow in size, eventually becoming contiguous as more trees die without being replaced. The native prairie is restored, one clearing at a time.
Photo credit: Tom Olson.
Culture and Connection
This rewilding effort is much about cultural restoration as it is about ecological repair. For millennia, First Nations shaped understood bison behaviour, hunting them as they seasonally migrated. Bison were a part of their food systems, culture and connection to the land. Honouring this deep relationship, the Olsons have formed strong partnerships with members of various First Nations near the bison rewilding projects.
Private-Sector Led, Values-Driven.
This project’s success is rooted in family leadership, where they take a unique and powerful role, often doing what governments and NGOs cannot. Much of the critical land that needs restoration and rewilding is privately owned, and in many cases, it’s families who hold the key to long term impact. Unlike public institutions, families can commit across generations, unaffected by shifting political priorities or budget cycles. They can make decisions quickly and can change actions based on adaptive management and stay on course without needing to compromise for public funding or political approval. This independence allows them to make bold, values-driven actions, making families essential partners in large scale rewilding projects.
Tom Olson’s work is a model for bold, ecosystem-scale rewilding, reviving landscapes, biodiversity, and cultural connections. Now this is a blueprint for restoring entire regions!
Meet the Rewilders
- Jack Olson: Tom’s late father, a school teacher, who loved bison and became a true bison whisperer.
- Thomas Olson: International tax lawyer, lifelong conservationist, bison rewilding leader since 1992, and co-author of major conservation texts including WWF’s Bison Conservation Management.
- Tom’s children: Hyrum, Joshua and Asher and their families ( a total of 16 grandchildren).
- Trustees of the Olson Family Trusts who are charged with preserving the project lands for rewilding for future generations.
- Many scientists who unselfishly donate time including Brad Stelfox, Steven Tannas, John Nishi, Walter Wilms and to the Manitoba Crown Lands civil servants who have been ardent supporters of our bison rewilding.
The Global Rewilding Alliance is honoured to have Tom Olson as one of our Champions who support our core team, work and overarching, ambitious vision.
