This article engages with notions of conservation in the Anthropocene from a history-of-science perspective. It does so by looking at an iconic case of infrastructure development that since the 1970s continues to cause controversies amongst wildlife experts: the Trans-Alaska Pipeline System (TAPS). I examine how, from the 1970s onwards, the TAPS functioned as an experimental device for ecologists to test the adaptability of migratory caribou to changed environments and their dependency on unaltered ranges. Based on archival research, published reports and interviews, I show that arguments about animal learning, despite assigning a more active role to caribou in the conservation process, did not result in more inclusive forms of development that respected ecological processes and the various stakes of the caribou. In fact, a focus on caribou crossings as an easily observable, yet sole, indicator of the pipeline's impact resulted in a simplified representation of environmental relationships, that was used by the oil industry to argue for additional extraction projects. Arguments based on the material interdependencies of caribou with their environment, though seemingly similar to traditional arguments about range preservation, emerged as part of conservationists’ attempts to account for the ecological stakes of caribou, other animals and people.