This study investigates the importance of interregional mobility along the Eastern Silk Roads during the Mongol period, highlighting the interconnectedness of postal and pilgrim networks in eastern Central Asia, with a particular focus on mid-fourteenth-century changes in the multifaceted dynamics of overland mobility under Mongol rule. By referencing an extensive corpus of Old Uyghur and Middle Mongolian administrative texts, as well as pilgrim inscriptions, the research provides a nuanced understanding of the relationship between the Mongol administration and the postal system within it, and how they were connected with pilgrim activities. The article uncovers valuable insights into how mobility patterns changed over time. Furthermore, a comprehensive analysis of the geographical aspects of these networks reveals enduring links between the Eastern Tianshan Region and the Gansu Corridor, whilst also underlining the expansion of pilgrim networks during the Mongol period. The research also explores the societal implications of these mobility networks, highlighting the importance of religious affiliation and social status in overland mobility. This comprehensive analysis illuminates the Eastern Silk Roads and presents a unique perspective on the interplay of political, religious, and socio-economic factors that shaped the history of the region during Mongol rule.