Mount Hood is Oregon’s highest peak (11,239 ft.) and the fourth highest peak in the Cascade Range.
Mount Hood has had at least four major eruptive periods during the past 15,000 years. The last three occurred within the past 1,800 years from vents high on the southwest flank and produced deposits that were distributed primarily to the south and west along the Sandy and Zigzag rivers. The last eruptive period took place around 170-220 years ago shortly before the arrival of Lewis and Clark in 1805. Minor 19th-century eruptions that were witnessed from Portland were in 1859, 1865 and 1903 A.D. When Mount Hood erupts again, it will severely affect areas on its flanks and far downstream in the major river valleys that head on the volcano. Volcanic ash may fall on areas up to several hundred miles downwind.
Mount Hood holds a total of twelve glaciers (Palmer, Zigzag, Reid, Sandy, Glisan, Ladd, Coe, Langille, Eliot, Newton, White River and Coalman Glaciers). Though Palmer Glacier is now referred to as a snow field as opposed to a glacier by modern geologists, which would now make a total of eleven glaciers on the mountain.
Mount Hood also is the headwaters for several major rivers including the White, Salmon, Sandy, Zigzag, and Hood Rivers which are all part of the tributary system of the Columbia River.