The Painted Hills of Eastern Oregon tell the story of climates past. Fifty million years ago the region was lush and tropical. It is now a sublimely rugged landscape in a semi-arid climate.
The red and tan layers of the hills reflect the climatic cycling between warm/wet and cool/dry, which occurred between 34 and 28 million years ago. Clay type, moisture levels, and the amount of oxidized iron present in the soil determined the hills� colour palette.
The hills� ancient soils are mixed with past lakebeds and river deposits. Scattered about the hills are fossil leaves, remnants of the broad-leaf deciduous trees that once grew on the edge of those long-vanished lakes and streams.
The Painted Hills are part of the John Day Fossil Beds National Monument.
Images: flickr.com
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