Oregon has an extensive geologic history, which is viewable from roadside videos. There are also videos of various landforms in the state created by geologic actions. Like other Pacific Northwestern states, Oregon has many volcanoes. Mount Hood and Mount St. Helens are two volcanic peaks close to Portland. The geologic history of the whole Pacific Northwest was influenced by the great Missoula Floods which has left its mark on the geology of the Columbia River gorge. The geology of Eastern Oregon also features the mammal fossil beds at John Day, which include the Painted Hills. The Pacific Northwest also faces the potential of a massive earthquake, due to the Cascadia subduction zone.