Between the early twentieth century and the 1960s, the Indian state began to incorporate the easternmost Himalayas. This article illuminates this state-making process by examining its material and communicative culture, embodied in tour diaries. These diaries were not private reflections written during one's spare time but the compulsory output of administrative tours. Often followed by more reflective notes, their perceived insights were used to determine local or general policy changes. Drawing on a literature that sees paperwork as constitutive of bureaucracy, this article argues that tour diaries exemplified and buttressed a certain form of frontier governance, marked by itinerancy and personalization well into independence. In their historical development, their language and materiality, their administrative usage, tour diaries embodied more than anything else the contingent, spatially uneven, and fractured nature of Indian state-making in the Himalayas, revealing the importance of process geographies anchored in paperwork circulation for its sustenance. Transmitted whole or extracted into policy files, diaries tied wandering officers together in a distinctive community of practice, policies, and ideas – preserving the fiction of the frontier state as a coherent whole in uncertain circumstances. As much as through maps, regulations, and routes, the frontier was made through writing.