The building of Šargan Railway, as they usually call the part between Užice and Vardište, begun on the 1^st of March 1921, by the Sarajevo Direction. Because the process was very slow, the Minister of Transport in The Kingdom of SCS decided to change the way of building. On October 1921 the railway was rented at the auction to the enterprise "Fenix", precisely, the part between Užice and Šargan tunnel. From Šargan to Mokra Gora, including the tunnel bellow Šargan, the construction was committed to the enterprise of Nikola Plavšić. The finalizing date was 24^th of April 1924.

After they have taken away the business from the firm of Nikola Plavšić, The Committee for the Finalizing of Šargan "Eight" Project finished the works on the committed part (22.8 km) and the first train passed the railway on January 25^th, 1925. The parts on this track were Šargan - Vitaši - Jatare (7.5 km), Jatare - Mokra Gora (7.8 km) and Mokra Gora - Vardište (7.5 km). At the same time, several gaps, bridges, supportive walls and tunnels were built and one of them, Šargan tunnel was 1,666 meters long.

Beside the attractive technical solution on the sides of Šargan, the railways that served as an example of successful overcoming of climb on a short distance, the railway also had other characteristics. The Jatare Station served only as a railway-crossing station and no ticket has ever been sold in it. The frontier tunnel with Vardište, beneath the Balvan hill, number 53, in its portal had a sculpture of a Serbian soldier which stands on the crown of the yellow-black Monarchy, and at the end of a tunnel, on the Serbian side, stand the name of Alexander I that ruled at that time, and beside that also the symbols of the Serbian peasant: cropper and hammer.

This strait railway had a great economic, politic and military-strategic importance for the new state, The Kingdom of Serbs, Croats and Slovenians. The railway engaged over 500 people from Užice to Mokra Gora.