The range is south of and runs parallel to the Wunaamin-Miliwundi Ranges (Formally King Leopold Range) and is mostly made from heavily eroded limestone, or karst, with the ridges composed of an ancient Devonian reef system.
They feature the impressive Windjana Gorge and Tunnel Creek and Geikie Gorge that were formed over 350 million years ago as part of the same limestone reef.
The Fitzroy River cuts through the range at Geikie Gorge, while the Lennard River is responsible for the formation of Windjana Gorge.The Barker River also carved Barker gorge through the range.
The highest point in the Napier Range is Mount Behm that is 325 metres (1,066 ft) above sea level.