This ecological system occurs throughout much of the western U.S., typically in broad basins between mountain ranges, plains and foothills between 1500 and 2300 m elevation. Soils are typically deep, well-drained and non-saline. These shrublands are dominated by Artemisia tridentata ssp. tridentata (not as common in Wyoming or Montana but possibly on stabilized part of Killpecker Dunes in Wyoming) and/or Artemisia tridentata ssp. wyomingensis (predominant in Wyoming and Montana). Scattered Juniperus spp., Sarcobatus vermiculatus, and Atriplex spp. may be present in some stands. Ericameria nauseosa, Chrysothamnus viscidiflorus, Purshia tridentata (not commonly in Montana or Wyoming), or Symphoricarpos oreophilus may codominate disturbed stands (e.g., in burned stands, these may become more predominant). Perennial herbaceous components typically contribute less than 25% vegetative cover. Common graminoid species can include Achnatherum hymenoides, Bouteloua gracilis, Elymus lanceolatus, Festuca idahoensis (not in Montana or Wyoming), Hesperostipa comata, Leymus cinereus, Pleuraphis jamesii (not present in northeastern portions of the range), Pascopyrum smithii, Poa secunda, or Pseudoroegneria spicata (not in Wyoming). Some semi-natural communities are included that often originate on abandoned agricultural land or on other disturbed sites. In these locations, Bromus tectorum or other annual bromes and invasive weeds can be abundant. Most Artemisia tridentata ssp. wyomingensis communities in Wyoming are placed in Inter-Mountain Basins Big Sagebrush Steppe (CES304.778); the shrubland system is more restricted in environmental setting than the steppe. Dunes in the Red Desert have areas of large basin big sage with very dense canopies. In Wyoming, this system is likely to only contain Artemisia tridentata ssp. tridentata.
Information Source: http://www.natureserve.org/explorer/