For National Fossil Day, we"re looking at the mesmerizing Painted Hills, found in the John Day Fossil Beds National Monument in Oregon. Those stripes of red, tan, orange, and black were formed over tens of millions of years, the different layers in the claystone hills reflecting changes in the climate over that period. The monument itself is divided into three units, Painted Hills, Clarno, and Sheep Rock. In the latter, you"ll find the Thomas Condon Visitor Center with a paleontology lab and a museum displaying hundreds of fossils. In the fossil beds, the remains of more than 100 species of mammals have been found, including saber-toothed tigers, turtles, and opossums, as well as many fossilized plant species. While the landscape might sometimes look otherworldly, it offers us a peek into Earth"s dynamic and fascinating history.