This paper explores the production of geographical knowledge in Qing Mongolia focusing on the gap between the Military Governor’s and the local officials’ understanding of territory. While the Qing state became reliant on local Mongolian officials to draw maps and submit textual descriptions of their land, imperial officials also sought to impose a certain vision of the territory that was aligned with institutional compilations and legal codes--such as the Huidian and the Lifan yuan zeli—and yet divorced from local practices. In 1835, the heads of the league of Secen Qan in Eastern Mongolia wrote to the Military Governor to explain that some Mongolian banners under their jurisdiction were separated by large undefined tracks of land that could not be mapped as part of any banner. This constituted a challenge to the state officials who requested the setting of clear-boundaries between banners while stipulating that no territory should be left out of the locally-produced maps. Teams of mediators were dispatched by the central state to meet with sub-banner officials from both parties who had to agree on the location of each boundary markers, which had to be carefully recorded and mapped. Ultimately, I argue that the geography of the Qing Mongolian steppe was constituted through a complex negotiation process where the state ideology conflicted with customary herding practices that required a flexibility and mobility.