2 Ecotypes - 8 Covered Species
Shortgrass species assemblage:
Sagebrush obligate assemblage:
The Thunder Basin Grasslands Prairie Ecosystem Association coverage area spans 13.2 million acres in northeastern Wyoming and southeastern Montana. This includes Campbell, Converse, Crook, Niobrara, and Weston counties in Wyoming along with portions of seven additional counties in Wyoming and three in Montana.
Current members of the Association own over 1.2 million acres of land within this mixed ownership landscape. Other lands include Thunder Basin National Grasslands administered by the USDA Forest Service through three local grazing associations, Bureau of Land Management lands, state lands, and additional private lands not currently in the membership of the Association.