The Petermann Ranges is a mountain range in central Australia. It spreads about across the border between Western Australia and the southwest corner of the Northern Territory. The highest point is above sea level. The ranges were formed about 550 million years ago, in an event called the Petermann Orogeny. They are made mostly of granite, sandstone and quartzite. The greater Petermann Ranges consist of several sections of ridges and hills. In the Northern Territory, these sections include the Dean, Mannanana, Ilyaralona, Curdie and Piultarana Ranges, the Pottoyu Hills, and several isolated mountains. In Western Australia, it includes the Hope and Dean Ranges.