ABSTRACT Transnational Politics of Road Building in 1960s Petén, Guatemala Barbara Bottini-Havrillay In the 1960s, as part of the US government’s Cold War strategy to fight communism in Latin America, the US and the Guatemalan militaries performed joint road development efforts to open Guatemala’s frontier region of Petén for agriculture and economic development. Two decades later, the same militaries that managed these road projects in Petén committed genocide against the indigenous Maya in other parts of Guatemala. While violence that took place in Petén is not considered genocide, it was part of a period in the civil war in which military violence was classified as genocidal by the UN. Despite previous findings that new roads in Petén were a catalyst of military violence, road building in Petén has yet to be studied comprehensively from this perspective. Drawing on oral history interviews with former US military advisors, photo albums, memoirs and newspaper articles collected at the Center for Mesoamerican Research in Guatemala, this study discusses how making roads in Petén assisted in creating the ideological preconditions and means of transport for the Guatemalan military. More precisely, this paper examines how road building and its military leadership improved the logistical capabilities of the military in Petén and reinforced eugenic ideologies about the “racial health” of the Guatemalan nation.