The Maranoa is a threshold. To the east lies the rich, cropped farmland of the Darling Downs; to the west, the dry maze of the Channel Country, where rivers spread into braided channels and vanish into the desert. The Maranoa sits between them, an eastern edge of Queensland's enormous, mostly arid South West. Two rivers define it: the Balonne and the Maranoa itself, the region's main catchments, gathering what rain falls across thousands of square kilometres of low country. Three highways stitch it together, the Warrego, the Carnarvon and the Balonne, thin ribbons of bitumen crossing distances that swallow them whole. The towns are small and far apart, Roma the largest, then Mitchell, St George and Goondiwindi, each a punctuation mark in a long, level sentence of grass and scrub.

This is rangeland, country shaped for sheep and cattle rather than the plough. The dominant trees tell the story: mulga, a hardy acacia whose leaves graziers cut and drop for stock in drought, and brigalow, the dense scrub that once covered millions of hectares before much of it was cleared for grazing. The climate is sub-tropical and unforgiving, long stretches of heat and dust broken by rain that can turn dry creek beds into temporary lakes. A rural, country life predominates here, organised around the rhythms of livestock and the watching of the sky. Properties are measured not in acres but in square kilometres, and a neighbour can live an hour's drive away across a single fence line.

Long before Mitchell rode through, this was the homeland of Aboriginal peoples whose territories met across the Maranoa's rivers. The Mandandanji, sometimes called the fishing-net people, held a vast tract of country taking in the Maranoa and Balonne north of St George, with Mitchell, Roma and Surat all within their lands. The Gunggari country centres on the Maranoa River and overlaps with the Mandandanji, Kooma, Bidjara and others, a web of nations whose boundaries followed the water. When the surveyors and graziers arrived in the 1840s, they wrote new names over old ones, but in Maranoa the old name survived. Every signpost in the district still carries the memory of a question asked at a riverbank, and the answer a Mandandanji speaker gave: duck, egg, this place.

For a century and a half the Maranoa's wealth came from wool and beef, drawn slowly from the surface of the land. Then the country gave up a second secret. Beneath the mulga lies coal, and bound within that coal is methane, coal seam gas, locked in the rock for millions of years. Its extraction has reshaped the region in a single generation. Rigs and pipelines have spread across grazing leases, work camps have risen on the edge of quiet towns, and Roma in particular has swelled with the rapid arrival of money, machinery and people. The Maranoa today holds two economies in uneasy balance: the old life of stock and seasons that still defines its character, and a newer, faster industry pulling energy from a kilometre below the duck-egg river.