This thesis seeks to integrate existing scholarly frameworks of populism, resource nationalism, and ethno-environmentalism in order to create a comprehensive understanding of Morales and the MAS. From 2006 until 2019, President Evo Morales and the Movimiento al socialismo (MAS) led Bolivia to global prominence. Experts lauded Morales and the MAS for apparent development successes and democratic expansion in a nation long known for its chronic poverty and conflict. Still, by the time of his controversial resignation, several socioenvironmental conflicts had diminished his reputation as an ethno-environmental champion, revealing the tensions inherent in pursuing resource nationalist development in an ethnopopulist state. While existing scholarship on the subject views populist and resource nationalist strategies and policies separately, their functional convergence in the Isiboro Sécure National Park and Indigenous Territory (TIPNIS) conflict demonstrates the necessity of an integrated framework. An integrative examination of the TIPNIS conflict reveals that the MAS prioritization of modernist development above all else. The Bolivian case provides a unique avenue for insight into progressive populism and ethno-environmental governance across Latin American politics, where commitments to aggressive visions of developmentalism characterize parties and political actors across the political spectrum.