[1] During the 1920s, this line was consolidated as a key infrastructure for Asturian industry, and plans were devised to extend it to La Robla in León.

[2][3] As a consequence of the political turmoil that suffered Asturias due to the Asturian Revolution in 1934, the initial plans to extend the line to León were ultimately abandoned.

[4][1] In the latter half of the 20th century, railway freight transport lost its economic significance, and Ferrocarril de El Vasco accumulated a considerable amount of debts.

[8] The lack of investment in its infrastructure, the opening of new road sections branching from the A-66 highway leading to Oviedo and the closure of the Fuso de la Reina branch to Oviedo due to an urbanistic project called the Green Belt caused that its number of passengers dwindled every year until the service from Baiña to Trubia was discontinued in 2009, thus disconnecting the two lines that used to run on the old Ferrocarril del Vasco line.

[13] The security system ASFA, installed in 2021, is not well adjusted to the characteristics narrow-gauge lines, thus train services are slower than decades ago.