Climate, Habitat, Flora & Fauna


Bison on the National Bison Range

  • Summers are generally warm and dry
  • Precipitation averages about 13 in/year
  • Approximately 70% of the annual precipitation falls in the winter as snow
  • Humidity is generally low
  • Average winter temperatures range from -28°C to 0°C (-28°F to 32°F)
  • Average summer temperatures range from 21°C to 30°C (70F's to high 90F's)


bighorn sheep at the National Bison Range

The National Bison Range (NBR) is largely Intermountain Bunchgrass Prairie, which is similar to the Palouse Prairie found in Washington and Idaho. Intermountain bunchgrass prairie is one of the most endangered ecosystems in North America. Once covering the intermountain valleys from the Rockies west to the Cascades and from southern Alberta/British Columbia south to northern Utah/Nevada, it now is restricted to less than 100,000 hectares due to agriculture and overgrazing (Daubenmire 1970). The NBR is the 2nd largest remaining tract (9000 ha); it was never farmed and has been protected since 1908 as a bison refuge. Prior to 1908, NBR was a cattle ranch for less than 15 years.  


Vegetation is dominated by grasses, especially Idaho fescue (Festuca idahoensis), rough fescue (Festuca campestris), and bluebunch wheatgrass (Pseudoroegneria spicata). Large mammalian herbivores including bison (Bison bison), elk (Cervus canadensis), bighorn sheep (Ovis canadensis), mule deer (Odocoileus hemiones), whitetail deer (Odocoileus virginianus), and pronghorn antelope (Antilocapra americana) can all be found on the NBR.  

Forested areas can be found at higher elevations on the NBR. These forested areas are dominated by Douglas Fir (Pseudotsuga menziesii) and Ponderosa Pine (Pinus ponderosa).


Species Lists 

The following species lists are provided by the National Bison Range: