Geologists long rejected the notion that cataclysmic flood had ever occurred—until one of them found proof of a Noah-like catastrophe in the wildly eroded river valleys of Washington State. After teaching geology at the University of Washington for a decade, I had become embarrassed that I hadn’t yet seen the deep canyons where tremendous Ice Age floods scoured down into solid rock to sculpt the scablands. So I decided to help lead a field trip for students to see the giant erosion scars on the local landforms.We drove across the Columbia River and continued eastward, dropping into Moses Coulee, a...