The Simpson Desert is a large area of dry, red sandy plain and dunes in the Northern Territory, South Australia and Queensland in central Australia. It is the fourth-largest Australian desert, with an area of . The desert is underlain by the Great Artesian Basin, one of the largest inland drainage areas in the world. Water from the basin rises to the surface at numerous natural springs, including Dalhousie Springs, and at bores drilled along stock routes, or during petroleum exploration. As a result of exploitation by such bores, the flow of water to springs has been steadily decreasing in recent years. It is also part of the Lake Eyre basin. The Simpson Desert is an erg that contains the world's longest parallel sand dunes. These north-south oriented dunes are static, held in position by vegetation. They vary in height from in the west to around on the eastern side. The largest dune, Nappanerica or Big Red, is in height. History Aboriginal history Aboriginal people have lived in the Simpson Desert for at least 5000 years and continue to do so today.The Wangkangurru people lived in the Simpson Desert using hand-dug wells called mikiri from long before European colonization until the Federation Drought. Post-colonisation Explorer Charles Sturt, who visited the region from 1844 to 1846, was the first European to see the desert. In 1880, Augustus Poeppel, a surveyor with the South Australian Survey Department, determined the border between Queensland and South Australia to the west of Haddon Corner, and in doing so, marked the corner point where the States of Queensland and South Australia meet the Northern Territory. After he returned to Adelaide, the links in his surveyor's chain were found to have been stretched. Poeppel's border post was too far west by 300 m. In 1884, surveyor Larry Wells moved the post to its proper position on the eastern bank of Lake Poeppel. The tristate border is now known as Poeppel Corner. In January 1886, surveyor David Lindsay ventured into the desert from the western edge, in the process discovering and documenting, with the help of a Wangkangurru Aboriginal man, 9 native wells, and travelling as far east as the Queensland/Northern Territory border. In 1936, Ted Colson became the first nonindigenous person to cross the desert in its entirety, riding camels. The name Simpson Desert was coined by Cecil Madigan, after Alfred Allen Simpson, an Australian industrialist, philanthropist,