The creation of greenspace in cities is often spoken of as if it were the result of orderly planning or regulation. Sydney did have a plan to conserve greenspace on the urban fringe but the 1948 Cumberland County Planning Scheme carried little real power to implement this goal in the face of population growth and expansion which was far higher than had been predicted. Working class residents in Sydney’s south western suburbs after World War 2 did not wait for planning or regulation. These people in low-income and newly subdivided suburbs expected little from government and took matters into their own hands, dragging local councils along with them until they had assembled a string of locally-managed and, at times, locally-constructed greenspaces along the banks of the Georges River for which they then demanded the designation of ‘national park’. In doing so, they were building on a long history of Aboriginal and then early settler occupation of these lands in collective recreational, cultural and highly socialised uses. They had seized on two of the key characteristics of the ‘national’ park as it had been defined in the United States and in Australia in the later nineteenth century: as a site for protection of indigenous ‘nature’ and as a democratic space ‘for the people’. Some of their management strategies are today decried as damaging to the environment, but the local park committees saw themselves not only as carving out and creating public recreational spaces but as protecting and extending what they understood to be ‘natural’ native floral and faunal environments, which was one of the reasons they demanded the ‘national park’ designation. This paper explores the underlying factors in this grass roots making of greenspace.