The Travelling Stock Route and Reserve (TSR) network is an historical grazing reserve network under threat, where public alarm has continued over the potential sale of reserves. Present debate on the future of the TSRs is often hindered by a lack of data, as knowledge of the historical extent of TSRs is deficient. This paper documents the original extent of the New South Wales TSR network and changes during 1884–2017, and discusses the key drivers of reserve loss since the late nineteenth century. Research using archived literature showed that, in 1884, the New South Wales TSR network comprised 4,413,728 ha. Comparisons of TSR acreage from that time with present estimates revealed that the reserve network has declined by 54% since its inception. Most reductions in TSR area during 1884–2017 have occurred in the Eastern (88%) and Central (78%) regions of the state, where competing land demands are greatest. Technological changes in transport, environmental pressures and economic changes in the grazing industry were identified as key drivers of TSR loss. These findings support concerns over the efficacy of the TSR reserve network, where the extent and impacts of past government decisions to sell off TSRs has been grossly under-estimated.