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Bison on the Prairie at Midewin

Midewin National Tallgrass Prairie, National Forest Foundation, The Nature Conservancy and many others partnered to bring the bison back to Midewin.

The Midewin bison herd is a small conservation herd. The herd was introduced at Midewin in October 2015 as a 20-year experiment in restoring the landscape to native tallgrass prairie. The grazing of the herd reintroduces disturbance that is important to reviving and sustaining a more diverse habitat of native grasses for wildlife on 1,200 acres of non-native prairie area.

Citizen scientists, volunteers, partners and staff are monitoring any noticeable increases in native prairie wildlife found at Midewin. The data they are collecting will be helpful in telling whether the grazing of the herd, and the varying lengths of different species of grasses created by their grazing, is encouraging a return of a wider variety of native Illinois plants, animals and insects.


About the Bison Project

Midewin Bison Project


Prior to European settlement Bison ranged over much of North America, freely roaming the landscape. Bison have been and are a key component of many prairie ecosystems, and Midewin’s management plan, which was developed with much public involvement, included introducing bison as a way to restore native tallgrass ecosystem and grassland bird habitat.

In December 2014, Prairie Supervisor Wade Spang signed an environmental decision document that allows a small bison herd to be introduced at Midewin on a long term experimental basis

The site the bison are located at had to meet several criteria, including: proximity to the Prairie Learning Center, vast amounts of baseline data for grassland bird populations, rolling topography for panoramic viewing; room for sub-pastures, soil type conducive to native prairie grasses and forbs, and had to be free of army infrastructure. 

Once picking a site that met those criteria work began on a 6 foot tall exterior fence and a 5 foot tall interior fence to keep the bison in their pasture, keeping in mind that bison can do a 6 foot vertical jump and the average bull weighs at least 2,000 lbs and a female can be anywhere from 800 to 1,000 lbs. 

While cattle currently graze on parts of Midewin, as a grassland management tool, bison grazing preferences are quite different from those of cattle. Part of the experiment is to determine if bison grazing will promote forb, grass and shrub diversity that is more compatible with native tallgrass prairie. The integration of bison into Midewin’s restoration practices will also look at if the bison provide a higher quality habitat for grassland birds and other animals, when compared to prairie habitat maintained by cattle grazing.

Another part of the experiment is to provide safe public education opportunities about bison, their life history and role in prairie ecosystems.

Success of the project will be measured with data collection and analysis, including monitoring grassland bird populations, native grass and forb populations; and visitor-bison interactions.  As the project is monitored we will adapt management approaches as needed to benefit the prairie, bison and public. 



big bison in a field


The herd was introduced at Midewin in October 2015 as a 20-year experiment in restoring the landscape to native tallgrass prairie.

Bison: Live Camera

Live Camera

On Friday, December 9, 2016 a webcam was installed in areas where the bison have been known to graze.

Close-up of a Bison

Viewing and Learning

Midewin staff and a trained group of Volunteer Rangers are available to discuss the bison introduction project with visitors at our Welcome Center and the Iron Bridge Trailhead area. Information and maps will be available at both locations.

Bison: Learning and Viewing


The history of the Bison experiment

Bison - Media


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