In 1947, Commonwealth Hill was having a fine season. Good rains had brought up an abundance of fresh green feed, and the sheep were fat. But another kind of news was moving through the district that year, carried station to station: word that the Woomera weapons range was to be expanded, and that runs like Commonwealth Hill, Bulgunnia, Roxby Downs and Andamooka would lose land, and with it their wool clip. The rumours proved true. The station lies inside the Woomera test range, and the graziers had to make their peace with it. Byron MacLachlan, who held the Commonwealth Hill lease in 1947, worked with a consortium of pastoralists and lawyers to hammer out an agreement that let the sheep work continue without interfering with the long-range weapons project. Wool and warfare would have to share the same ground.

Sharing ground with a missile range carried real danger. By 1957, as the British and Australians advanced their rocket testing programme at Woomera — including early Skylark sounding rockets — the safety of the pastoralists living downrange was named a key concern. That year the Minister of Supply, Howard Beale, met with the graziers who might be in the path of the trials and announced that the Commonwealth would pay to install blast-proof shelters on the affected stations. It was an extraordinary arrangement: families raising sheep in one of the emptiest corners of the continent, going about lambing and shearing while rockets arced overhead and the government built bunkers in case something fell short. The work of the station went on, season after season, inside the boundary of the world's largest land-based test range.

Strip away the human history and Commonwealth Hill is a window onto deep geology. The station sits on the margin of the Gawler craton, a block of crust more than a billion years old, here buried beneath sand sheets and travelling dunefields. The vegetation tells the story of a hard climate: mulga and myall, hardy acacias that survive on almost nothing, standing over perennial grasses with the occasional salt lake and its crescent of wind-piled sand, a lunette, marking where ancient water once lay. The mineral wealth locked in that old crust has drawn prospectors too. In 2011, after a federal review of mining inside the former missile-testing area, an iron-ore exploration company was finally granted permission to begin work on a prospect here, a reminder that even the most restricted ground is never entirely still.