The song is gentler than the history. In September 1894, the great shearers' strike was tearing through outback Queensland. At Dagworth station, north of Winton, striking shearers fired their rifles and torched the woolshed, killing more than a hundred sheep. The station owner and three policemen pursued one of the strikers, a man named Samuel Hoffmeister, known as "Frenchy." Cornered near Combo Waterhole, Hoffmeister shot himself rather than be taken. A real man, real desperation, a real death by this water. The defiant swagman of the song who cries "You'll never catch me alive" carries the ghost of a striking worker who meant it.

In 1895, the poet Andrew Barton "Banjo" Paterson visited the Macpherson family at Dagworth. The story goes that at a picnic by Combo Waterhole, Bob Macpherson told Paterson about the drowned striker and his belief that the billabong was haunted. Christina Macpherson played a tune she half-remembered, and Paterson set words to it. From a labour tragedy and a borrowed melody came a ballad about a wandering swagman and a stolen jumbuck. Paterson softened the politics into folklore, and in doing so wrote a song that would outlive every name involved. Whether the ghost was Hoffmeister's or the country's own, it has never left the water.

The waterhole holds an older labour story too. Stretched across the Diamantina's braided channels are stone-pitched overshot weirs, low causeways of fitted stone built in 1883 by Chinese labourers to manage the river's floods. Thousands of Chinese workers came to the Australian colonies in the nineteenth century and often did the hardest, least-credited work on stations and goldfields, frequently in the face of hostility. Their weirs still lie in the riverbed near Combo, quietly outlasting the men who laid them, much as the carved waterhole has outlasted the swagman. And older still: this is Koa country. The Koa people have followed the Diamantina's braided channels for generations, and in 2021 the Federal Court recognised their native title over more than 31,000 square kilometres of this country, including this waterhole. The country here remembers its people, even when the history books forget their names.

Look at the wider land and a stranger story emerges. Combo Waterhole sits at the northern rim of a roughly circular zone about 130 kilometres across that Geoscience Australia has flagged as a crustal anomaly, a faint scar buried in the rock. Its cause is unproven, but one leading idea is that an asteroid struck here around 300 million years ago, long before the Diamantina, the coolibahs, or the swagman. If so, the gentlest folk song in Australia was born on the floor of an ancient impact crater. The waterhole keeps that secret too, layered beneath the billabong like everything else this country chooses not to say out loud.

Today Combo Waterhole sits inside a small conservation park, roughly 130 kilometres north-west of Winton off the Landsborough Highway. A walking track leads through Mitchell grass downs and red-soil plains to the water's edge, past the old stone weirs. In the dry season the billabong shrinks to a series of pools fringed with coolibah; after rain the Diamantina spreads across its channels and the whole landscape greens. It is an easy place to stand quietly and feel the weight of it: a labour death, a haunting, an anthem, and an asteroid, all gathered at one bend in an outback river that most travellers would otherwise drive straight past.