Petrified Forest National Park
The Petrified Forest area was designated a National Monument on December 8, 1906. The Painted Desert was added later, and on December 9, 1962, the whole monument received national park status.
The park overs 93,532.57 acres (378.513 km²). Hiking opportunities are limited. The longest trail in the park extends for only two miles; the others are one mile or less. However, a road does extend through much of the park. Landmarks include the Agate House, built of petrified wood, and the Agate Bridge, a petrified log spanning a wash.
The petrified wood of the Petrified Forest is the 'State Fossil' of Arizona. The pieces of permineralized wood are fossil Araucariaceae, a family of trees that is extinct in the Northern Hemisphere but survives in isolated stands in the Southern Hemisphere. During the Upper (Late) Triassic, this desert region was moist and mild. In seasonal flooding, the trees washed from where they grew and accumulated on sandy delta mudflats, where they were buried by silt and periodically by layers of volcanic ash from volcanoes further to the west. The volcanic ash was the source of the silica that helped to permineralize the buried logs, replacing wood with silica, colored with oxides of iron and manganese.
Theft of petrified wood has remained a problem despite protection and despite the fact that nearby vendors sell wood collected legally from private land.
The Petrified Forest (1936) is a film, a gangster thriller starring Bette Davis, which uses the Petrified Forest area as an atmospheric isolated setting.