Critical scholars have addressed land use models and related technologies by pointing to their epistemological underpinnings and the social consequences of visibilities and invisibilities induced by these instruments to different forms of governance. More recently, in addition to reaffirming the old dictum that the map is not the territory, some scholars have analyzed how land use models can shape perceptions, narratives and policy, and in this way "make" the territory and the state. In this study, we adopt the notion of sociotechnical imaginaries to highlight the role of land use models and basin-wide development schemes in the emergence of military developmentalism in the Brazilian Amazon. We show that earlier surveys of the Amazon were created in order to substantiate territorial claims and to guide the exploitation of natural rubber and other extractive resources. Mapping of the rivers as arteries with limited upland assessment implied a view of the Amazon as an immutable and invincible nature where resources were given as elements of natural landscapes. The approach of economic sectorial mapping that had dominated earlier surveys began to shift during and especially after World War II in an effort to imagine Amazonia as a separate and identifiable policy space which transformation would be possible with the application of development frameworks, such as the one derived from Tennessee Valley Authority (TVA). Likewise, experts from the United Nations Food and Agriculture Organization played a key role in providing land use models and assessment that "proved" the economic viability of large-scale colonization projects. This article points out that the extensive occupation and ongoing destruction of the Amazon rainforest was also informed by US large-scale planning regimes infused with technoscientific approaches derived mostly from Global North scientific institutions. Those concepts underpinned imaginaries of an integrated region whose "planning surface" would be oriented by the idea of the "Legal Amazon", subject to a technocratic, centralized and authoritarian style of developmentalism. In this way this paper shows how land use models are not mere representations of the territory but also carriers of sociotechnical imaginaries that coproduce radical changes in social and natural landscapes.