When Japanese geographer Mamiya Rinzō traveled up the Amur River in the spring of 1808, he was carrying out a cartographic project at the order of the shogunal astronomical service and mapped Japanese interests in the Sino-Russian borderland. Contrary to the common conception of early modern Japan’s “seclusion” from the outside world, the Tokugawa Shogunate staked out its interests proactively and scientifically in the northern frontier. Since the early 1700s, Russian expeditions, staffed with German and French scientists, had drawn attention to the region. Indigenous communities around the sea mediated between these emerging powers and reconfigured identities and affiliations in changing contexts––as traders, guides, or workforce in proto-industrial enterprises. As borders solidified across the region, and territories were swapped between Russia and Japan repeatedly, locally embedded actors continued to figure as agents of knowledge into the 20th century. This project seeks ways to position this transimperial interaction zone in global history, with a specific focus on the long-term interaction of science, environmental change, and local economies.