In the second half of the twentieth century, natural gas became the fuel of Iran’s future. During that time, gas ceased to be burned as waste in the country’s southern oil fields as the Iranian state claimed the right and the ability to exploit the vast resource. Intertwining it with broader narratives of development and national sovereignty, officials both before and after the 1979 revolution framed gas use as simultaneously making and asserting Iranian advancement. Gas and its infrastructure became sites where Iranians imagined their country’s impending greatness, becoming monumental testaments to the independence and progress they dreamed of for their country. That gas would come to play this role in Iranian society was not only a product of decades of effort and imagining by Iranians of all backgrounds, but by the very contours of Iran’s physical geography. I argue that the sociotechnical imaginaries of natural gas that shaped Iran as it developed in the second half of the twentieth century were deeply entangled with the country’s landscape and the global distribution of industrialized societies. The international firms that operated Iran’s oil fields prior to the 1979 revolution had long resisted exploiting the associated natural gas they extracted as a byproduct of oil, deeming the cost of the pipelines necessary to reach Europe, the nearest major market, as rendering Iranian gas uncompetitive. It thus fell to Iranians to make their own markets, a process shaped by the specific geologies of the country’s gas deposits, the differing compositions of the reserves they sought to tap, and the geography of Iran itself. Both the successful and failed projects that Iranians pursued were deeply shaped by the constraints and opportunities presented by the geography of Iran’s gas. They dreamed of a regional network of chemical fertilizer plants that took advantage of the proximity of Iran’s gas fields to the Persian Gulf; they built a cross-country pipeline that carried refined gas from the southern fields to Iran’s northern centers of population and industry; and worked to power cities with cleaner gas energy, helping counter local topographies that caused air pollution to accumulate in urban areas. Going beyond accounts of post-war Iran that center questions of religion, ideological contestation, and Great Power meddling, this paper sheds light on the crucial role that the country’s geography, channeled through the provision of natural gas, played in defining the Iran its citizens imagined and worked to build.