John Day Fossil Beds National Monument
near Mitchell, Oregon
The appropriately named "Painted Hills" is one of the three units that make up the John Day Fossil Beds National Monument, and is located 75 miles east of Bend, Oregon. They were formed under similar conditions as Capitol Reef in Utah and the Painted Desert and Blue Mesa in Arizona.
The colorful layers correspond to various geological eras, formed when the area was an ancient river floodplain. The black soil is lignite that was vegetative matter that grew along the floodplain. The grey coloring is mudstone, siltstone, and shale. The red coloring is laterite soil that formed by floodplain deposits when the area was warm and humid. There are a large number of fossil remains of early horses, camels, and rhinoceroses here.
The Hills are best photographed in the late afternoon when they take on a yellow cast. Tones and hue appear to change from one visit to another, as the claystones differ with changing light and moisture levels.