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For more than a century, the bison herd at Daniels Park has represented something extraordinary: the first wildlife reintroduction in Colorado. Since 1938, Denver Mountain Parks has cared for this herd, and today, that story is entering a powerful new chapter.
This summer, in partnership with Denver Mountain Parks, Highlands Ranch Backcountry Wilderness Area (HRBWA), Colorado State University, Sanctuary Golf Course, and the TallBull Memorial Council, Denver Zoo Conservation Alliance’s Great Plains team helped expand the grazing range of this historic herd onto land that bison haven’t roamed in more than 150 years.
A Herd With Deep Roots
The Daniels Park bison herd’s origins trace back to the very early 1900s, when Denver Zoo Conservation Alliance helped preserve some of the last bison remaining in Colorado. Today, their descendants have helped repopulate bison herds across Colorado and the United States, representing a living legacy of what conservation done right can accomplish.
“This herd are the descendants of animals that were brought to Denver Zoo Conservation Alliance back in the very early 1900s when those bison were the only bison left in the state,” said Tim Luethke, DZCA’s Great Plains Restoration Coordinator. “Today this herd has helped to repopulate Colorado bison herds and bison herds across the United States. This is a hugely important bison herd.”
A Landscape Built for Bison
The grasslands surrounding Daniels Park are unlike almost anywhere else on the Front Range. When connected with the Highlands Ranch Backcountry Wilderness Area and Cherokee Ranch, this landscape represents one of the largest remnants of untilled prairie in Colorado; a living ecosystem that has never been broken by a plow.
“We want to think about the next 100 to 1,000 years of pasture management for these bison,” said Luethke. “As long as the City of Denver exists, this herd is going to be here, and we want to make sure we’re being as good of stewards as we can for this grassland ecosystem. It’s super diverse. Most of it is in really good shape, and keeping it that way is our responsibility.”
Bison aren’t just inhabitants of this landscape, they’re architects of it. As ecosystem engineers, their grazing and physical movement create healthy soil and dynamic habitat for the plants and animals that share this prairie with them. Expanding their range isn’t just good for the bison; it’s good for the entire ecosystem.
GPS Collars, Field Days, and the Science of Stewardship
Before the herd could move onto new pasture, our teams got to work. Spanning two years of field work, DZCA’s Great Plains Field Conservation and Veterinary Medicine teams joined Denver Mountain Parks, Colorado State University, and the TallBulls for two bison immobilization days at Daniels Park. The goal was to fit male bison with GPS collars and solar ear tags.
The dual-tracking approach was intentional. The GPS collars provide location updates every 15 minutes, while the solar ear tags report hourly. Having two independent systems means teams have redundant warning capabilities if any bison wander outside their new pasture, allowing for a quick response without requiring another field anesthesia procedure.
While immobilized, DZCA’s Veterinary Medicine team also collected DNA samples and other health metrics to assess the herd’s overall wellbeing and genetic lineage. Data that will inform management decisions for years to come.
Shannon Dennison, Director of Denver Mountain Parks, described why this collaboration is so essential.
“Denver Mountain Parks doesn’t have the staff and expertise to do veterinary care or to have the number of scientists and wildlife specialists needed to make good management decisions and safely handle the bison,” she said. “And Denver Zoo Conservation Alliance doesn’t necessarily have the amount of land and space that we have here. So it’s really a perfect partnership — we have the land and the animal resources, and Denver Zoo has the people. It works really well.”
What the Data Will Tell Us
The collars and ear tags aren’t just safety tools, they’re scientific instruments that will help answer questions about short-grass prairie ecosystems that have never been fully understood.
“The collars also have cameras, so we’ll get vegetation data on what the bison are eating and primarily targeting,” Luethke explained. “That’s going to help us understand how they’re influencing these grasslands and influencing biodiversity. There’s a huge lack of information on how bison affect biodiversity in short-grass prairie ecosystems. There’s a lot of data in mixed grass and tall grass — but we want to answer those questions for our herd close to home in Denver.”
The data could also inform fire management strategies, parasite control, and future dung beetle release sites, all part of a holistic approach to grassland health.
“Getting those really long-term data sets is going to be super revealing,” Luethke said. “It’ll probably spawn a whole bunch of master’s student projects, PhD student projects, and just a lot of wonderful research for many, many years to come.”
A Living Relationship
Among those who showed up for the bison is Lewis TallBull Jr., whose presence at Daniels Park carries a meaning that goes far beyond pasture management.
“The bison need help. They need a voice. They’ve been forgotten. Nearly erased. Just like my Cheyenne and Arapaho people,” he said. “We consider ourselves bison people. There was no telling where the animal ended and the human began because we would drape ourselves in bison. Everything we used for living came from the bison. The bison was everything to us.”
TallBull speaks of the bison not as wildlife to be managed, but as relatives to be honored.
“We want to look at these bison like a brother or a sister, or a grandma, or a grandpa, or a grandchild. We want to look at these bison like a relative. And being able to be amongst my relatives… it’s very empowering.”
His vision for the future is rooted in the same generational thinking that guides the best conservation work.
“Everything that we do right now is going to affect us seven generations down the line. Whatever we do now is very important. Being able to be here and work with the bison and support them and protect them — it’s not for me. It’s for our grandchildren’s grandchildren.”
What Comes Next
The long-term vision for this partnership is ambitious and deeply meaningful: to restore bison to their native grasslands, expanding habitat across one of the most significant prairie ecosystems remaining on Colorado’s Front Range.
This summer’s expansion onto the Highlands Ranch Backcountry Wilderness Area is a milestone, but it’s also just the beginning. By combining scientific research, collaborative partnerships and meaningful conservation action, we’re creating a future where bison and Colorado’s grasslands can thrive together. With GPS monitoring in place, teams will continue tracking herd movements, refining pasture management strategies, and working together to ensure that Colorado’s oldest conservation bison herd continues to thrive for the next hundred, the next thousand years.
Because as Lewis TallBull reminds us: the water comes first, then the four-legged, then the winged, then Mother Earth herself. And when we tend to all of it together, we stay grounded.
Just like the bison.
Denver Zoo Conservation Alliance’s Field Conservation Programs work to protect native wildlife and ecosystems across Colorado and worldwide.
Learn more about our field conservation work here.
