This work proposes to investigate the historical process of formation of the territory, the main actors, the adopted strategies and the clashes between the agrarian extractive frontier and the socio-environmental frontier in the Southwest of Pará. To carry out this work, technical materials were analyzed, such as studies, research and surveys, as well as journalistic articles produced about the region of Southwest Paraense in recent years. As a result of the research, it is observed the formation in the region of a mosaic of protected areas, possible thanks to the coalition of socio-environmentalist movements. There was, however, an agroextractive counter-offensive in the region, based on environmental, agrarian and indigenist deregulation and the dismantling of federal inspection bodies that led to an acceleration of the advance of all the fronts that make up the agrarian extractive frontier.