Lake Amadeus - NT

Lake Amadeus is a large salt lake in the southwest corner of Australia's Northern Territory, about 50 km north of Uluru (Ayers Rock). Amadeus is 180 kilometres (110 mi) long and 10 kilometres (6.2 mi) wide, making it the largest salt lake in the Northern Territory.

The first European to discover the lake, the explorer Ernest Giles, encountered it in 1872. Giles originally intended to honour his benefactor Baron Ferdinand von Mueller with the eponym Lake Ferdinand. However, Mueller prevailed upon Giles to instead honour King Amadeo I of Spain (reigned 1870-1873, known in English as King Amadeus I), who had previously bestowed honour on him. The lake's expanse proved a barrier for Giles, who could see both the as yet undiscovered Ayers Rock and Kata Tjuta but could not reach them as the dry lake bed wasn't able to support the weight of his horses. The next year, William Gosse climbed and named both rises.

In late October 1872 Giles made several attempts at crossing the lake to reach Mount Olga, all failed and some were near disastrous. One foray nearly cost Giles his expedition when his horses broke through the salt crust and were immediately,

“floundering about in the bottomless bed of this infernal lake ~ We were powerless to help them, for we could not get near owing to the bog, and we sank up over our knees, where the crust was broken, in hot salt mud. All I could do was to crack my whip to prevent the horses from ceasing to exert themselves, and although it was but a few moments that they were in this danger, to me it seemed an eternity. They staggered at last out of the quagmire, heads, backs, saddles, everything covered with blue mud, their mouths were filled with salt mud also, and they were completely exhausted when they reached firm ground". - Ernest Giles – Australia Twice Traversed.

The impenetrable barrier of Lake Amadeus and the harshness of the surrounding country defeated Giles on his first attempt at crossing to the west coast of the continent.

The following year William Christie Gosse had similar difficulties, crossing Giles tracks several times, searching for a way south, but whereas Giles followed the lake to the N.W. Gosse travelled S.E. and crossed the lake at a narrow neck, at "latitude 24° 50', longitude 131° 30'," and continued south and west to happen upon the most remarkable natural feature he had ever seen,

"being one solid rock (fine conglomerate) two miles long, one mile wide, and 1100 feet high, a spring coming from its centre. I named it Ayers Rock." (after the then Chief Secretary of South Australia, Sir Henry Ayers).

In August 1886, Henry Tietkens, Giles Second in Command on his 1873 and 1875 expeditions, reminded members of the South Australian branch of the Royal Geographical Society, that very little was known about Lake Amadeus, "on our present maps we see a leg of mutton shaped figure, bounded by dotted lines, but the real extent of this interesting feature is unknown to us", no doubt with an eye to future employment Tietkens suggested that the Society, the Government and the citizens of South Australia had a duty to rectify this oversight. On the 22nd of July 1889, as leader of The Central Australian Exploring and Prospecting Association Expedition, he reported from Erldunda that his expedition was safe and well, but had found no gold or grazing lands and "Mount Unapproachable in Long's Range marks the western extremity of Lake Amadeus".

The Horn Expedition crossed the eastern end of the lake in June 1894, and noted that the surface of the lake was found to be tolerably firm, the horses only sinking to the depth of a few inches". In October 1902, W. R. Murray, the surveyor on R. T. Maurice's expedition to the north coast, reported on the journey and had little to say about Lake Amadeus, "we crossed Lake Amadeus at its western end, after having made several unsuccessful attempts to get over it at its broader parts".

By 1930 the bounds and nature of Lake Amadeus were well enough known, the north-western extremity lay in the vicinity of Long's Range and to the south east it was negotiable at longitude 131° 30', and from hard experience uncrossable at its wider parts, no watercourses entered the lake and it did not flood, no valuable minerals had been discovered in the area and the grazing lands were ephemeral, if not risky. The lake bed was a salt mud bog, variously described as sterile, barren and dangerous. In June 1930 Lake Amadeus was in the news when the Mackay Ariel Survey Expedition put the finishing touches to the map, finding the lake somewhat smaller than expected and nothing favourable to add to a forbidding record.