The construction of the road began 23 years ago to link Diktel, the headquarters of Khotang with Gaighat of Udayapur.

In 1994, the then Prime Minister Manmohan Adhikari had inaugurated the construction work at Bokse in Gaighat.

The 156 kilometre long Sagarmatha Highway has been constructed with the primary aim of linking Diktel with the national road network.

[1][2] The highway starts at Indo-Nepal border called Thadi and runs north towards Lahan.

From Gaighat to Phoksingtar the distance is 53 kilometres (33 mi) and the whole section runs on Lower Himalayas which is called Mahabharat Hills.