The Christmas flood of 1964 was a major flood in the United States' Pacific Northwest and some of Northern California between December 18, 1964, and January 7, 1965, spanning the Christmas holiday.Considered a 100-year flood,it was the worst flood in recorded history on nearly every major stream and river in coastal Northern California and one of the worst to affect the Willamette River in Oregon. It also affected parts of southwest Washington, Idaho, and Nevada.In Oregon, 17 or 18 people died as a result of the disaster, and it caused hundreds of millions of dollars in damage. The flooding on the Willamette covered 152,789 acres (61,831.5 ha).The National Weather Service rated the flood as the fifth most destructive weather event in Oregon in the 20th century.California Governor Pat Brown