Sand Dunes, The Dalles, Oregon, 2001Photograph by Jim RichardsonIn a curious juncture, a wrinkled span of desert dunes pours into the Columbia River Gorge in The Dalles, Oregon. Eons of erosion by the mighty Columbia River carved this dramatic 80-mile-long (130-kilometer-long) gorge into the Cascade Range. Declared the nation's first National Scenic Area in 1986, the area is known for its 4,000-foot (1,220-meter) canyon walls, lush rain forest, and dozens of waterfalls.