At the end of the nineteenth century, the seeming unavailability of “free” land elicited declarations of the closure of the frontier. But in the twenty-first century, it seems like more frontiers are opening than ever before. The Arctic is a prime example of this trend. With climate change melting away the Arctic ice cap, multinational corporations, national governments, and indigenous corporations all see opportunities for development. Even as the polar seas and the lands around them are rapidly and unpredictably changing, plans are underway to build new infrastructure like ports along Russia’s northern coast and a highway to the Arctic Ocean in Canada. More than geophysical factors, however, are motivating this infrastructure push. Political, economic, and technological drivers are leading developmental interests to seek to shorten the distance between global markets by bridging the supposed “infrastructure gaps” that exist in not only the Arctic, but also places like Central Asia, Siberia, and beyond. Using a mix of qualitative methods and remote sensing, this dissertation analyzes the scalar politics of infrastructure development in two contemporary frontiers: the Arctic and Russian Far East. This research first aims to explain how contemporary frontiers are conjured as spaces in need of development and globally articulated infrastructure by focusing on the Arctic as a regional example (Ch. 1) and the Canadian Arctic as a national example (Ch. 2). I then use two case studies to illustrate how transportation infrastructure projects are spearheaded both from within and outside frontier spaces, drawing on the cases of the indigenous Inuvialuit people and their role in lobbying for and building Canada’s first highway to the Arctic Ocean (Ch. 3) and the Singaporean government’s foray into Arctic development initiatives (Ch. 4). Expanding beyond traditional methods in political geography, I review advances made in using multitemporal night light imagery to study socioeconomic dynamics (Ch. 5) and apply techniques from this field to study regional development in Russia and China (Ch. 6), two countries that experienced vastly different development trajectories following the collapse of communism. Coming full circle, I consider how post-Soviet Russia, suffering from a major infrastructural deficit that is illustrated both by fieldwork and remote sensing, may be a lucrative yet precarious investment site for China’s Belt and Road Initiative (Ch. 7). A central conclusion of this research is that the development of frontiers is politically and economically conditioned, locally negotiated, and cyclical rather than linear.