The Painted Hills is a geologic site in Wheeler County, Oregon that is one of the three units of the John Day Fossil Beds National Monument along with Sheep Rock and Clarno. It totals 3,132 acres and is located 9 miles northwest of Mitchell, Oregon. The Painted Hills are listed as one of the Seven Wonders of Oregon. The layers of color for which the site is n…The Painted Hills is a geologic site in Wheeler County, Oregon that is one of the three units of the John Day Fossil Beds National Monument along with Sheep Rock and Clarno. It totals 3,132 acres and is located 9 miles northwest of Mitchell, Oregon. The Painted Hills are listed as one of the Seven Wonders of Oregon. The layers of color for which the site is named can be traced back to cycling periods of wet and dry climate conditions associated with the transition from the Eocene epoch to the cooler, more temperate Oligocene epoch. The different layers of colors are due to the soil being composed of a combination of mudstone, siltstone, shale and lignite.