This paper examines North Korea’s border politics along the inter-Korean border before the Korean War, focusing on the provincial division and the border revisions of Gangwon north of the 38th parallel. It traces how the division of Korea by foreign powers and the provincial boundary modification by the nascent North Korean state shaped northern Gangwon’s distinct way of becoming a North Korean province. Rather than focusing on certain areas of Gangwon, the present study takes northern Gangwon as a whole, examining how the border revision affected the political relationship between the province’s old and new administrative centers, Cheorwon and Wonsan, respectively, and North Korea’s capital Pyongyang. This paper advances the notion of borderland, inspired by Etienne Balibar’s rethinking of the concept of de/territorialization from the peripheral perspective, highlighting the power of bordering practices in maintaining the imposition of homogeneous symbolism upon heterogeneous realities. Through the lens of borderland, this research reveals the historical transformations of northern Gangwon from a remnant of an arbitrary division to a political arena of changing spatial relations and eventually to an abstracted territory not without uncontrollable elements within itself.