Introduction : the Lake Missoula flood story -- The Ice Age -- Ice sheets and ice lobes -- The Lake Missoula floods -- Discovering the floods -- The channeled scablands -- Water gaps -- The Columbia River Gorge -- Clark County Washington -- Gravel pits and rock quarries -- Portland area inundation -- Portland area flood channels -- Erratic boulders -- Tualatin, Yamhill & Willamette valleys -- The mad rush for the exits -- The water departing through Portland.