Petrified Forest National Park is a national park of the United States in Navajo and Apache counties in northeastern Arizona. Named for its large deposits of petrified wood, the park covers about 346 square miles, encompassing semi-desert shrub steppe as well as highly eroded and colorful badlands. The park's headquarters is about 26 miles east of Holbrook along Interstate 40, which parallels the BNSF Railway's Southern Transcon, the Puerco River, and historic U.S. Route 66, all crossing the park roughly east–west.