Arunachal Pradesh remained largely inaccessible by rail until the early 21st century. Before 2014, the state had only 1.26 km of railway line within its borders, with Bhalukpong station in East Kameng district being the sole station.
On April 7, 2014, history was made when the first passenger train ran to Naharlagun, near Itanagar, marking Arunachal Pradesh's entry onto India's railway map. This milestone connected the state capital to the broader Indian railway network.
The Harmuti–Naharlagun section spans approximately 21.75 km and was built at a cost of around ₹590 crores. Initially sanctioned in the 1996–97 Railway Budget as a metre-gauge line, it was later converted to broad gauge. The alignment was finalized in 2010, and the line was commissioned in 2014.
Several strategic railway projects have been proposed and surveyed to enhance connectivity and support national security:
The Indian Railways continues to expand its network in Arunachal Pradesh, aiming to connect remote and strategic locations. Projects such as Pasighat–Parshuram–Wakro and Bame–Aalo–Mechuka have been approved, with surveys completed. These efforts are part of a broader ₹1.2 lakh crore umbrella project to enhance connectivity in the northeastern states.
The commissioning of railway lines in Arunachal Pradesh has significantly improved accessibility, reduced travel hardships, and boosted economic and tourism potential. With continued investment and strategic planning, the state is poised to become a vital hub in India's northeastern railway network.