East of the Cascade Mountains, Washington’s climate is arid and the terrain is desert-like. Summertime temperatures can exceed 100 degrees Fahrenheit in regions such as the Yakima Valley and the Columbia River Plateau. This is an area of rolling hills and flatlands. During the last Ice Age, 18,000 to 13,000 years ago, floods flowed across this land, causing massive erosion and leaving carved basalt canyons, waterfalls and coulees known as the Channeled Scablands. This scene of a desert canyon was photographed from the Cowiche Canyon Trail near Yakima, Washington State, USA.