Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Gibson Desert covers a large area in the state of Western Australia and is still largely in an almost "pristine" state. It is about 155,000 square kilometres (60,000 square miles) in size, making it the 5th largest desert in Australia, after the Great Sandy, Great Victoria, Tanami and Simpson deserts. It lies between Lake Disappointment and Lake Macdonald along the Tropic of Capricorn. The Gibson bioregion includes extensive areas of undulating sand plains and dunefields, low rocky/gravelly ridges and substantial upland portions with a high degree of laterite formation.