In the late Triassic period, more than 200 million years ago, ash from volcanoes in the sea west of Pangea became mixed with mud and other debris, including animal and plant remains, along the coastal lowlands of what is now northeastern Arizona. Monstrous monsoonal floods carried onto these plains the downed logs of great conifers from the highlands of Colorado and New Mexico. Buried quickly in the oxygen-free, silica-rich mix of ash and mud, the logs petrified without decay, often preserving their finest details. Forests of these Triassic giants lie scattered across the badlands of Petrified Forest National Park. Blue Mesa, named for the blue and grey colors of bentonite clay that arise from carbon in once living tissues, is in many regards the most beautiful and photogenic area in the Petrified Forest.