Raging Ice Age floodwaters carved spectacular features throughout eastern Washington, creating unique landscapes. As the floodwaters rushed across the region, they followed existing rivers and streams until they overwhelmed them, then found their own way toward the ocean by going over or around large obstacles and carving new routes wherever they could. Landscape features preserve clues to these floods, including the shape of the Palouse Hills across Highway 261 and streamlined hills whose tear-drop shape points in the direction of the floodwaters. When temporary Lake Lewis pooled behind Wallula Gap, most of the Pasco Basin region, including the Tri-Cities and Sacajawea State Park, lay under hundreds of feet of water. At Lyons Ferry Park, at the confluence of the Snake and Palouse rivers, Ice Age flood features can still be seen, including views of Palouse River Canyon.