Pronghorn making their way across a Montana prairie
Pronghorn in Montana Grassland Pronghorn in Montana's Northern Prairie © Dave Hanna/TNC

Places We Protect

Northern Great Plains


One of America's Most Significant Remaining Grasslands

Montana's Northern Great Plains encompass some of the largest and most significant native grasslands remaining in the United States.

These glaciated plains, blanketed in native mixed grass, support what may be the largest assemblage of grassland species left on the Northern Great Plains. These include disappearing birds, such as mountain plover, burrowing owls, chestnut-collared longspurs and Sprague’s pipits. Interspersed sagebrush steppe also provides habitat for one of the healthiest greater-sage grouse populations in the world.

Grassland Habitat Montana's prairies support the richest mix of grassland birds in the U.S. They are the last stronghold for many of these species.

Although other treks may be better known, migrations by pronghorn through Montana’s Northern Great Plains are the longest land mammal migrations in the continental United States. Pronghorn travel more than 500 miles roundtrip on their seasonal migrations, more than twice as far as Wyoming’s Path of the Pronghorn. Greater sage-grouse make a similarly record-setting journey for the species, more than 100 miles one way each spring and fall.

The grasslands also host deer, elk and such rare species as black-tailed prairie dogs, swift fox, and the black-footed ferret—the rarest mammal in North America.

Sage Grouse Monitoring Montana rangeland ecologist Kelsey Molloy conducts field monitoring of the greater sage grouse. Each spring males gather on these lands known as leks, to impress females with their display. After mates are chosen, hens lay 6-10 eggs. Chicks hatch about four months later.


In Montana, the greatest threat to native prairie has been conversion to cropland, so-called “sod busting.” Over the last 25 years, more than 25 million acres of grassland have been destroyed in the U.S. That’s twice the rate of forest loss and faster than the Amazon rainforest is disappearing.

The push for energy development is also putting the prairies in peril as grasslands are converted to crops for biofuel and broken by development associated with oil and gas exploration.

Hundreds of miles of fencing create obstacles to migrating animals, such as pronghorn. Poorly maintained and designed fencing can even prove deadly for deer, elk, pronghorn and birds.

Invasions of noxious weeds and exotic diseases, such as Sylvatic Plague and West Nile virus, are also threats to native prairie.

Making Good Progress

A new study, co-authored by TNC scientists, presents evidence that private land is absolutely essential to protect the epic wildlife migrations of the Northern Great Plains. The study also has good news: not only is it still possible to protect these pathways, conservation is on track toward success.

Since wildlife doesn’t recognize ownership lines, conservation must span these boundaries, and the work TNC has been doing for nearly a decade is paying off. Guided by cutting-edge science with partners at the University of Montana, we have successfully targeted the most crucial private lands in need of conservation. As a result, we have permanently conserved much of the private land within the path of pronghorn migration. A side benefit is the protection of habitat for several species of declining grassland birds. Willing private landowners have played a vital role in this success.

The study also notes that many wildlife migrations on the Northern Great Plains fall within the same timeframe and duration. That makes coordinating conservation measures—such as opening gates to allow movement of pronghorn, deer and elk, or keeping cattle off pastures while sage-grouse are using them for mating—much easier.

Goals and Strategy

The Conservancy’s goal is to conserve grassland through direct land protection and partnership with the local ranching community. We're using a three-pronged approach:

  • First, we are investing in science to help unlock even more of the undiscovered secrets of the northern plains.  We are using our 60,000-acre Matador Ranch as a center for learning that allows researchers and ranchers to work together. 
  • Second, we are employing the best conservation tools developed by science and engaging the people that live in the grasslands through the Matador grassbank. The grassbank extends wildlife conservation management on an additional 240,000 acres of cooperating ranches; it’s the most successful grassbank in the country. Additionally, by implementing a wildlife-friendly fencing program, we are removing barriers to movement for pronghorn and sage-grouse.
  • Third, we are permanently conserving grasslands vulnerable to habitat destruction through the purchase of conservation easements.

Make a Gift to Grassland Conservation

Support our work in Montana, including preservation of our Northern Great Plains, by making a charitable contribution today.