Converting disused railway corridors into multi-purpose spaces to achieve strategic sustainable mobility, leisure, and/or tourism objectives is an increasingly prevalent public policy issue. Previous literature suggests it is often bottom-up processes driven by networks of community-level actors that generate community support and political will to operationalise rail trail visions, though a lack of understanding of such ‘bottom-up’ advocacy processes exists. This study adopted the concept of participant-governed networks to explore the structure and function of a grassroots, community-based network which secured political support and financial commitment for a regional transport and tourism project encompassing construction of a rail trail in northern New South Wales, Australia. Our analysis shows this network comprised an intuitive core–periphery structure of community-minded actors who contributed an eclectic range of resources to consolidate broader political and community networks to advance the rail trail vision.