Portland lies on top of an extinct volcanic field known as the Boring Lava Field, named after the nearby bedroom community of Boring. The Boring Lava Field has at least 32 cinder cones such as Mount Tabor, and its center lies in southeast Portland. Mount St. Helens, a highly active volcano northeast of the city in Washington state, is easily visible on clear days and is close enough to have dusted the city with volcanic ash after its eruption on May 18, 1980. The rocks of the Portland area range in age from late Eocene to more recent eras.