Sand dunes at Hanford area viewed from across the Columbia River at Ringold
Dunes are the faint light area in the satellite image (USGS)
Having grown up in eastern Washington I found that while traveling or living any distance from eastern Washington I frequently had to explain that eastern Washington is dry. In fact, large swaths of eastern Washington is desert. Parts of the east side basin are so dry that it is marginal for even sage brush to survive. And there are several areas of sand dunes in this dry landscape.
Hanford sand dunes and Columbia River.
Irrigated land on the east side of the river is irrigated via the Columbia Basin Project
The largest dune field in eastern Washington is on the U.S, Department of Energy Hanford Reserve. A fair bit of the dune area at Hanford has become stabilized with vegetation hinting that for a time the area was even drier. But the core area of the Hanford dunes still contains a large active dune field. Public entrance to the dune fields at Hanford is restricted since the Hanford area was established as a nuclear materials production site. I got a glimpse of the Hanford dunes from across the river on a recent landslide inspection adventure.
The sand for these dunes is derived from from sands deposited by Missoula Flood waters that swept across the Hanford area depositing gravel, sand and silts. The dry climate and prevailing southwest winds has formed the dune fields which are slowly being blown into the Columbia River. Perhaps some of the sand from these dunes blown into the Columbia is now part of the sand dunes along the beaches of the southwest Washington coast.