Painted Hills By Matt Young August 15, 2009 12:00 MST Photograph by Michael Klaas. Photography contest, finalist in the “Minerals” category. Painted Hills – exposed strata of geological eras when this section of Central Oregon was a river floodplain. Colors are formed by layers of volcanic deposits that fell from eruptions in the Cascade Range 35 million years ago. John Day Fossil Beds National Monument, Oregon.