The Snake River near Twin Falls, Idaho, is barely discernible near the top center of this west-looking, low-oblique, color-infrared photograph. Visible north of the river is a large lava flow near the right center of the photograph. Water from the river provides irrigation for many of the agricultural areas in the Snake River Valley, a vast lava plateau built up by repeated outpourings of volcanic rock approximately 20 million years ago. Subsequent erosion and glaciation have produced a varied landscape of high plains, immense fields of volcanic rubble, deep gorges, and fertile volcanic soil in the Snake River Plain that produces abundant potato crops. Sand dunes are apparent near the bottom right of the photograph.