Darjeeling, April 15: If a study by the railways allows it, tourists can chug along the Teesta up to Sikkim, a proposal that has remained on paper for over a century.

A lone national highway — 31A — now links the Himalayan state with the rest of the country. Landslides, not rare during the rainy season, almost cut off the state from the mainland.

The Indian Railways is conducting a survey on the possibility of laying tracks between Sevoke, on the outskirts of Siliguri, and Rangpo in Sikkim, about 50 km away.

“The final report is being prepared and the task will be completed in four to five months. It will then be forwarded to the railway board (for a final nod),” a Northeast Frontier Railway spokesperson told The Telegraph over the phone from Maligaon in Assam.

Efforts to connect Sikkim by train had started over a century ago — around the time the Darjeeling Himalayan Railway was being set up to link the Queen of Hills with Siliguri.

The railways had then tried to build the Teesta Valley line, up to the Bengal-Sikkim border.

While the 82-km Darjee- ling-Siliguri toy train link was opened in 1881, work on the Teesta Valley line progressed slowly. The project suffered a setback when landslides wreaked havoc across the hills in 1899.

When the Siliguri- Kalimpong Road (now call- ed NH 31A) was realigned in 1907-08, work on the Teesta Valley line resumed and it was finally opened in 1915. Both the realigned road and the narrow gauge line followed, to a large extent, the course of the Teesta.

The final stop was Kalimpong Road Station, about 25 km from the Sikkim border.

However, the line was abandoned in 1950 after the railways suffered heavy damage because of landslides that year.

A landslide made Sikkim inaccessible to heavy vehicles for days last year. The ones that ferry tourists had to take an eight-hour detour to reach Gangtok, only about four hours drive from Siliguri at other times.

Veterans recall goods trains on the Teesta Valley line, ferrying oranges from Sikkim and Tibetan goods (especially wool), traded through the Jelepa-la pass.

The railway official said the route may not follow that of the old Teesta Valley line for the 50 km now under consideration.