Wallula Gap We experienced the wind of the Columbia Platform today - our shore plans were scrubbed because of excessive wind in flavor of heading upstream through Wallula Gap. Lucky us. It turned out wonderfully because of the chance to see beautiful clouds and sun-spotted hillsides against the backdrop of the Gap. A photographers dream. The Gap is a constriction in the Columbia River that was blasted out by the massive floods that sculptured half of Eastern Washington and the Columbia River Gorge at the end of the last Ice Age. The short geologic story of the Columbia Basin starts with continental docking, followed by mountain building and multiple massive layers of molten rock called basalt. The basalt was shaped to its present form by the massive floods from 15,000-12,000 years ago. Here is an example of the many layers of basalt that the floods tore at over a period of approximately 2,500 years. The process is being finished off with the everyday geologic tools of wind, water and gravity.