A Journey Through Time
There's a reason the Painted Hills are 1 of 7 of Oregon's Wonders. The colorful hills tell a very interesting story of the past and each color represents a different part. The red is made of laterite soil which is rich in iron and aluminum. This section formed by floodplain deposits when the region was warm and humid. Vegetation that grew along the floodplain created the black lignite soil. The grey color comes from mudstone, shale, and siltstone. As for the yellow...I couldn't find any information.