Northwest Exposures chronicles the events that shaped the region"s rock and landforms through the ages. The tale of the Northwest"s geology began more than two billion years ago when an ancient continent split, creating oceanfront property in what is now western Idaho. Pacific islands mashed into that coastline, making large parts of Washington and Oregon. These events were followed by monstrous volcanic eruptions, catastrophic ice age floods, and mountains rising to an accompaniment of earthquakes.