Cirsium pulcherrimum var. pulcherrimum
Variety pulcherrimum occurs from eastern Montana and northeastern Utah across Wyoming in the Wyoming Basin, Rocky Mountains, and western Great Plains to northern Colorado and northwestern Nebraska. It is likely that it occurs in southeastern Idaho as well. In the online Atlas of the Vascular Flora of Wyoming, several localities are plotted for var. pulcherrimum in Lincoln County, close to the Idaho state line. R. E. Brooks (1986) included Idaho in the range of C. pulcherrimum; I have not seen documentation for such occurrence. Cirsium pulcherrimum (i.e., var. pulcherrimum) is included in the list of Nebraska Plants of Special Concern.