, or narrow, thin rock faces. Then, water seeped into the cracks of the fins and froze and expanded, which caused chunks of sandstone to fall out and form a window. Water and wind continued to erode the window until it becameAmong the park's best-known arches are the Delicate Arch, which is depicted on the Utah license plate, and the— the largest of them all. Landscape Arch stretches 306 feet across, or about the length of a football field.
Nearly 200 million years ago, coniferous trees such as pines grew in this lowland area of what is now Arizona, though the climate was more tropical at the time. Fallen trees, somein diameter and around 200 feet tall, were covered in sediments as nearby rivers flooded from storms. Over time, multiple volcanic eruptions layered the area in volcanic ash, rich with silica.
The burial of these trees happened so quickly that the wood evaded decay normally caused by insects and oxygen. As the groundwater mixed with the volcanic ash and silica, it layered over the wood and turned the organic material into stone, also known as petrification. The resulting fossils are a beautiful menagerie of reds, yellows, oranges and whites. They somewhat resemble precious stones, which makes them an enticing souvenir. But as with all National Park lands, visitors aren't allowed to take anything from the site, including rocks, plants and animals. And for good reason, since removing any of these items can harm the local ecosystem or degrade the geological features..
. When visiting Petrified Forest National Park remember to take only pictures and leave only footprints.