Newberry is one of the largest Quaternary volcanoes in the United States, with a caldera that spans 6 to 8 km across. The center of the volcano is located about 35 km SE of Bend, OR.
Construction of the volcano began about 400,000 years ago; since that time it has erupted in a variety of styles ranging from basalt flows to far-reaching explosions of ash. A major explosion and collapse event about 75,000 years ago created Newberry's summit caldera. The caldera contains multiple hot springs, indicating that it is still hydrothermally active. These hot springs and multiple youthful lava flows indicate that the volcano could reawaken at any time.
The Cascades Volcano Observatory and the PNSN cooperatively operate 8 seismometers in or near Newberry caldera. On average, we locate 0 earthquakes within 10 km of the volcano each decade.