About 9 million years ago, the Yakima River flowed south from near Vantage to the Tri-Cities, and then turned west straight for the ocean through Badger Canyon west of Kennewick. Badger Canyon was once a waterway of the Yakima River, this pre-existing channel led the Yakima River to make tribute to the Columbia River at the current location of the city of Kennewick. Beginning nearly 15,000 years ago the Columbia Plateau was transformed by the successive Missoula glacial outburst floods. Much of the flood water made way down the Columbia river Channel where a 'choke-point' known as Wallula Gap caused the restriction of flow. Floodwaters began ponding near the Tri-Cities resulting in the back-flooding of the Columbia's tributary valleys. Badger Canyon was an entry point for back-flooding of the Yakima Valley, successive floods left behind thick deposits of sediments in Badger Canyon and the Valley beyond. These flood deposits which were deposited in large quantities in short amounts of time changed the ground elevation within badger canyon causing the Yakima River to re-route north of Red Mountain and enter the Columbia River by present-day Richland.