My favorite views of this region are found in and around Petrified Forest National Park.
I wrote about the preserved trees of Petrified Forest in the past, but the landscape itself is worth a closer look.
The rocks of the Painted Desert badlands are part of the Chinle Formation of the late Triassic Period. These sediments were deposited between about 225 and 205 million years ago in and around rivers and streams that blanketed the area. Composed mostly of soft, easily-eroded shale, mudstone, and volcanic ash, they also contain thin layers of sandstone, siltstone, and limestone.
This formation is rich in a variety of minerals that produce vibrant colors when weathered. Iron and manganese minerals are particularly common.
Despite the striking contrast between red and green/blue layers, they contain roughly equal amounts of iron minerals. The color difference is a result of varying water levels as these sediments were deposited. When water levels were low, the iron minerals were oxidized by atmospheric oxygen and turned red. When water levels were high, the iron minerals were cut off from atmospheric oxygen. In this reducing environment they turned green or blue.
The river deposits, preserved trees, and abundant vertebrate fossils demonstrate that this area was much different in the late Triassic. Waterways harbored numerous fish and amphibians. The wet climate supported forests of large coniferous trees and many other plants. These riverside woodlands were filled with early dinosaurs and the ancestors of modern reptiles and mammals.
Between the modern organisms, ancient fossilized organisms, geologic history, and breathtaking scenery, the Painted Desert is a worthwhile destination.