The red and yellow striped hills of the John Day National Monument are one of the great attractions in Oregon. The soft layers of rock are relics of volcanic ash which was transported by the wind from far away and deposited at this place. The hills undergo a constant weathering process during which iron minerals are formed, giving the rocks these splendid colours. Plants cannot root here - the bedrock is too soft and as a result rain water carves deep gullies in the surface. Even animals crossing the hills leave visible traces here. (aerial view)