Current ripple marks
47.228879°N 120.011530°W

The giant ripple marks caused by the Missoula flood can be seen from here.  Stop 8 in Baker et al.

"This viewpoint affords the opportunity to see one of the most spectacular zones of giant current ripples in the region (Fig. 29). West Bar is located on the western side of the Columbia River valley, which here has its bottom obscured by Wanapum Lake, a long reservoir with a pool elevation of 174 m that extends upstream from Wanapum Dam, located downstream ~40 km to the south. The West Bar giant current ripples (fluvial dunes) average ~8 m in height, ~110 m in spacing, and are composed of gravel with boulders up to 1.4 m in diameter (Baker, 1973a). The ripples occur at an elevation of ~210 m, while maximum megaflooding at this location may have reached as much as 400 m, although that flooding may have occurred before emplacement of the current ripple configuration "

Missoula Floods

The Missoula Floods (also known as the Spokane Floods or the Bretz Floods) refer to the cataclysmic floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age. The glacial flood events have been researched since the 1920s. These glacial lake outburst floods were the result of periodic sudden ruptures of the ice dam on the Clark Fork River that created Glacial Lake Missoula. After each ice dam rupture, the waters of the lake would rush down the Clark Fork and the Columbia River, flooding much of eastern Washington and the Willamette Valley in western Oregon. After the rupture, the ice would reform, creating Glacial Lake Missoula again.

• http://en.wikipedia.org/wiki/Missoula Floods
• Page 38 - Baker, V. R., 2016, Pleistocene megaflood landscapes of the Channeled Scabland: The Geological Society of America Field Guide 41