The Yakima Valley and Columbia Basin of Eastern Washington isn’t really named the “Columbia Desert” but it should be. Some of the most endangered habitat in Washington is located in these shrub-steppe and desert areas. The heart of the area has been developed into the Columbia Basin Project, the largest Federal irrigation project in the United States. It was conceived during the New Deal era and supplies irrigation water to about 700,000 acres out of a 1,100,000 acre project area. Today large swaths of Central and Eastern Washington appear bright green in satellite photos due to irrigation.
The entire area was once covered with colorful shrub-steppe; sage brush, bunch grass, forbs, perennials, and cacti. Today developed agriculture and invasive weeds dominate the landscape, with remnant populations of native desert and steppe plants in limited areas. Most people are unaware these plants even exist in Washington. I always get a kick from seeing these landscapes just 2 or 3 hours from Seattle.
Rare native desert plants include salvia dorri (Purple Desert Sage); opuntia polyacantha, opuntia columbiana and opintia fragilis; pediocactus simpsonii (Hedgehog cactus).