The Transandine Railway (Spanish: Ferrocarril Trasandino) was a 1,000 mm (3 ft 3+3⁄8 in) metre gauge combined rack (Abt system) and adhesion railway which operated from Mendoza in Argentina, across the Andes mountain range via the Uspallata Pass, to Santa Rosa de Los Andes in Chile, a distance of 248 km.

As of 2023, there are still freight train services between Los Andes and Río Blanco on the Chilean side running on the Transandine railway tracks.

It was initiated by Juan and Mateo Clark, Chilean brothers of British descent, successful entrepreneurs in Valparaiso who in 1871 built the first telegraph service across the Andes, between Mendoza in Argentina and Santiago in Chile.

The section between Mendoza and Uspallata was opened on 22 February 1891 and extended to Rio Blanco on 1 May 1892,[1] to Punta de Vacas on 17 November 1893, to Las Cuevas on 22 April 1903.

[3][4] The line followed roughly the ancient route taken by travellers and mule-trains crossing the Andes between Chile and Argentina and connected the broad gauge, 5 ft 6 in (1,676 mm), railway networks of the two countries, rising to a height of almost 3,200 metres at Las Cuevas where the track entered the Cumbre tunnel, about 3.2 km long, on the international border.

The Chilean Transandine railway was originally worked by Kitson-Meyer 0-8-6-0s rack and adhesion locomotives, two examples of which survive in Chile.

[1] In 2006, both the Argentine and Chilean governments agreed to refurbish the railway and make it functional by the year 2010, at an estimated total cost of US$460 million.

[7][8] In 2016 and after almost a decade of announcements and good intentions from both countries, the Transandine train that Argentina and Chile had been promoting since 2006 was finally postponed and without a recovery date.

The Government of Chile decided that the private initiative project presented by the Eurnekián group among other holdings, was not among its priorities in the plan to improve border crossings.

The Trasandino was removed from the list of border union issues, focusing on announcements related to improvements for car traffic in the bi-oceanic corridor.