United States (New Mexico, Wyoming, California, Nevada, Colorado, Arizona, Utah)
Description:
This alliance is dominated or codominated by Bouteloua eriopoda, Bouteloua gracilis, Pleuraphis jamesii, or Sporobolus airoides. It occurs in arid and semi-arid regions in the southwestern Great Plains, Colorado Plateau, southern Rocky Mountains, Great Basin, and northern Chihuahuan Desert.