Arkaroola owes its existence as a sanctuary to one remarkable man: Reg Sprigg, the same geologist who decades earlier had found the Ediacaran fossils that rewrote the history of life. In 1968, Sprigg bought the worn-out Arkaroola pastoral lease, land that had defeated generations of would-be pastoralists, and set about converting it from a grazing run into a protected wilderness. He understood this country as few others did, having surveyed it for minerals himself. His work in protecting the endangered yellow-footed rock-wallaby led to his appointment as a trustee of the World Wildlife Fund in 1979. Where others saw marginal ground or mineral wealth to be extracted, Sprigg saw a landscape worth keeping whole, and he devoted the rest of his life to it.

Arkaroola sits on country rich in uranium, and that wealth nearly undid it. For decades, exploration companies prospected the ranges, and the pressure intensified in the 21st century. In 2008, the company Marathon was found guilty of illegally dumping radioactive waste at sites within the sanctuary and ordered to halt drilling. When the government renewed a mineral exploration licence in 2010, allowing drilling to resume inside the protected area, the public revolted. A 2011 poll found 72 percent of South Australians opposed mining at Arkaroola. Bowing to extraordinary pressure, Premier Mike Rann announced in July 2011 that mining would be banned forever, and special legislation that October created the Arkaroola Protection Area, prohibiting mining, exploration, and grazing in the ranges. The wilderness had won.

Arkaroola's signature experience is the Ridgetop Track, a four-wheel-drive route carved along razorback spurs to Siller's Lookout, where the land falls away to reveal the salt shimmer of Lake Frome stretching toward the horizon. The track was built in the late 1960s by uranium explorer Bill Siller, and the lookout carries his name. Then there are the Paralana hot springs, where the rock itself is alive with energy: granite laced with uranium gives off heat as it slowly decays, warming water that bubbles to the surface at 62 degrees Celsius, hissing with radon, carbon dioxide, and helium. The radon is hazardous to linger near, yet on the floor of the springs an extremophile algal mat thrives in the heat and radioactivity, life clinging on where it has no right to be.

Far from any city, the air above Arkaroola is among the clearest and darkest in Australia, and in July 2023 it earned formal recognition as South Australia's first International Dark Sky Sanctuary, only the second in the country. The sanctuary runs three observatories, the newest built in 2019, and nightly the telescopes turn skyward while an astronomer narrates the show on a big screen. Overhead, the Milky Way blazes with a density of stars most visitors have never seen. By day, the country reveals its other extremes: this is among the hottest places in Australia, holding for decades the record for the nation's warmest overnight low. Harsh, ancient, and improbably alive, Arkaroola rewards those willing to travel to the edge of the map.