A very successful non-native species often seen in Wyoming and arid gardens is Artemisia ‘Powis Castle.’ It probably originated in the Mediterranean region, but it became popular when it was planted at Powis Castle in Wales, Wales being one of the leading best guesses for the birth place of St. Patrick.
Powis Castle is a hardy perennial for zones 4-9, forming a loose mound 1 -3 feet high and wide. It is drought tolerant and the deer do not love it- both very good reasons for using it in the garden.
If you are looking for a true native that serves the same purpose, consider Artemisia frigida (Fringed Sage) or Artemisia cana (Silver sage). Silver sage will tolerate more moisture and heavier soils. Fringed sage is a true high desert plant loving light soils, full sun, and little moisture.
If you let Fringed sage survive on natural rainfall it will hug the ground and, if seeded thickly, will produce a lovely, lacey ground cover. However, if you water it moderately you will be rewarded with a beautiful, silvery plant covered with 18 inch flower stalks in August.
As with any Artemisia I have grown or observed, if they are found in partial shade with extra moisture, they will be a lovely blue/grey green, but if it grows on the drier, sunnier end of its preferred habitat, it will develop a very dense tomentum on the leaves to guard against moisture loss, which gives it a fantastic silver sheen.
And of course the sages native to the Great Basin, High Plains, and Foothills of the Rockies are the source of the quintessential aroma of the west.