Petrified wood is a staple of southwestern North Dakota and is a geologic wonder in itself. It’s the fossilized remains of ancient trees that were trapped underground or underwater, without any oxygen. Minerals are deposited into the tree’s cells, and over time, turns the wood to stone. The original structure of the tree is preserved, down to the microscopic details. Petrified wood is very common in the rocky butte country of western ND, and is a reminder that this area of the great plains was once covered in trees that were later buried under a shallow sea, millions of years ago.