Steens Mountain photoThis photo of Steens Mountain taken by Vic CampĀ is one of ten chosen by the Geological Society of America to sell as notecards in honor of their 125th anniversary. The outcrop is composed of the ~16.7 Ma Steens Basalt, the oldest lithosptratigraphic unit of the Columbia River flood basalts. The unit is composed of a series thick compound flows (from 10-50 m) containing numerous thin (