By following different sites of mercury governance in Colombia, I intended to seek preliminary answers to the following questions: what would be the best way to promote an appropriate, socially just, and environmentally effective transition to a world without –or at least with much less– mercury in a country experimenting an ambitious political transition. What does it mean to declare a war against an unruly resource that is so hard to govern? How does this objective take form in practice and how does it affect different social groups? During six weeks, I visited two mining regions –the Andean area of Nariño and the Lower Cauca Basin River in Antioquia– and interviewed miners, gold traders, local government officers, and NGOs promoting sustainable commerce of gold. My preliminary conclusion is that as long as policy and technoscientific interventions aimed at halting mercury pollution keep overseeing local, contextual conditions in which ASGM takes place on the ground, not only these initiatives will not achieve their stated purpose of protecting health and the environment, but will also exacerbate inequalities among miners and perpetuate rural poverty. This experience was extremely useful for framing my research question. Now I have concrete elements to begin my dissertation research next year. Before conducting this fieldwork season, I had done research on other parts of Colombia, mainly the Amazon region.