Word travelled fast in the colonial frontier, and a ruby field promised the kind of wealth that made men abandon everything. By May 1888, prospectors swarmed the dry riverbed, chipping at the cliffs and sieving the sand of what they had named Ruby Gap. It was Central Australia's very first mining rush, narrowly preceding Lindsay's own discovery of gold at Arltunga, forty-five kilometres to the west. For a brief, dizzy moment the future looked written in crimson. So many stones came out of the ground that they flooded the market - and that flood, ironically, was the beginning of the end. When a commodity that should be rare suddenly isn't, buyers start asking why.

The questions reached the experts, and the experts reached a verdict. After extended debate, the gemmologists ruled in June 1888 that the glittering red stones were garnets - high-quality garnets, certainly, but garnets all the same, worth a fraction of the rubies everyone had imagined. The market did not gently correct; it crashed. News rippled across the field on 24 May 1888, and the dream that had pulled hundreds into the desert evaporated almost overnight. The rocks in the riverbed had not changed at all. Only the word attached to them had, and the word was everything. Today the park still draws visitors who scratch through the sand at Glen Annie Gorge - the gorge Lindsay named for his wife, Annie - hoping to spot the deep red garnets that fooled an entire colony.

One man did not leave. Within the park lies the grave of F. H. Fox, a miner who managed the MacDonnell Ranges Ruby Mining Company, and the timing of his death reads almost like a parable. Fox died on 25 May 1888 - the day after the announcement that turned everyone's rubies into garnets, that collapsed the company he ran, that ended the rush. Whether the news and the death are connected, no record says. The grave is known simply as Fox's Grave, and it sits at the end of a popular walking track, one of the very few visible relics the ruby rush left behind. The headstone that stands there now may not even mark the original spot. It is a fittingly uncertain monument to a boom built on a beautiful mistake.

Strip away the brief human frenzy of the 1880s and what remains is a place of quiet, ancient drama. The Hale River has carved Ruby Gap into towering cliff lines, walls of folded rock glowing in the low light of morning and evening, water lingering in shaded pools long after the surrounding land has dried. Reaching it is still genuinely remote - the approach runs through the Arltunga Historical Reserve and demands a capable four-wheel drive - which is exactly why the gorge feels untouched. The garnets that bankrupted a mining company are still scattered through the sand, free for anyone patient enough to look. The rush lasted barely two years. The gorge has been here, and held by the Arrernte, for a very long time before that, and will outlast every prospector by an immeasurable margin.