This trail follows the route of two mining railways. The first, which dates from 1874, used to link the iron and coal mines of the Valle de Quirós with the station at Trubia, a total of 30 km of track. A spur line used to join this route from Caranga de Abajo, linking it with the Teverga mines. This spur added an extra 10 km to the route, giving it a Y shape layout.

The line was used by light locomotives pulling ore filled trucks which barely coped with the steep inclines, especially when it came to braking on the way down. In the old days, the railways used to employ brakemen to ride on the wagons to apply and release the brakes when instructed to by the coded whistle blasts of the engine driver.    

The mining crisis dragged these railways down with them, and they were shut down in 1964. The Principality of Asturias first and later the Ministry of the Environment set about recovering these old railway lines to provide locals and visitors alike with one of the most outstanding Greenways in Spain.