Shrub-steppe is a type of low rainfall natural grassland. Shrub-steppes are distinguishable from deserts, which are too dry to support a noticeable cover of perennial grasses or other shrubs, while the shrub-steppe has sufficient moisture levels to support a cover of perennial grasses and/or shrubs.
The shrub steppes of North America occur in the western United States and western Canada, in the rainshadow zone between the Cascades, and Sierra Nevada on the west, and the Rocky Mountains on the east. They extend from south-central British Columbia down into southeastern Washington state, eastern Oregon, and eastern California, and across through Idaho, Nevada, and Utah into western Wyoming and Colorado, and down into northern and central New Mexico and northern Arizona. Growth is dominated by primarily low-lying shrubs, such as big sagebrush- Artemisia tridentata, and Purshia tridentata with too low of rainfall to support the growth of trees, though trees do occur. Other important plants are Bunchgrass- Pseudoroegneria spicata which have historically provided forage for livestock as well as wildlife, but are quickly being replaced by non-native annual species like Cheatgrass- Bromus tectorum, tumble mustard- Sisymbrium altissimum, and Russian thistle- Salsola kali. There is also a suite of animals that call the shrubsteppe home including Sage Grouse, Pygmy rabbit, Western rattlesnake, Pronghorn.
Historically much of the shrubsteppe in Washington State was referred to as "scabland" because of the deep channels cut into pure basalt rock by cataclysmic floods more than 10,000 years ago Channeled Scablands. Major threats to the ecosystem include overgrazing, fires, invasion by non-native species, development since much of it is at lower elevations and conversion to cropland, as well as energy development. Less than 50% of Washington State's historic shrubsteppe remains  and according to some estimates it is only 12 to 15% .
Shrub-steppe ecoregions of North America include: