The railway line was built in the second half of the 19th century to provide an outlet to the sea for the minerals extracted by the British Tharsis Sulphur and Copper Company from its deposits in the Tharsis-La Zarza mining basin.

The Tharsis-La Zarza region has a rich history as a mining basin, yet it wasn't until the 19th century that it became more extensively developed.

[5][6] The route ran from the Tharsis mines to the port of Corrales, situated on the Odiel River, near Huelva city.

While the primary purpose of the line was always mineral transportation, passenger services began in the late 19th century at the request of local residents.

The railway traffic reached its peak in the middle of the 20th century, when almost one million tons of ore were transported annually.

To enable Iberian gauge trains (1668 millimeters) to access the Corrales railway complex, RENFE installed a third rail on the original 1220 mm track.

Although the Gibraleón-Ayamonte line ceased operation in 1987, the Gibraleón-Mezquita-Corrales route continued to serve ore convoys for a brief period of time.

[12] In May 1991,[14] the Empalme-La Zarza railway branch ceased operations due to the mining crisis and ultimately closed in 1992.

The fate of the railway was sealed when in 1999, the company FESA-Fertiberia announced that it would not be renewing its purchasing contract for ore from Tharsis.

[note 1] Despite various proposals to repurpose the railway for tourist-recreational use,[17] similar to the Riotinto Tourist Mining Train, nothing has been done to date.

The main line spanned about 47 kilometers[18] over mostly flat terrain, with the necessary construction of several metal lattice bridges to cross the ravines of Meca, Medio Millar, Multa, San Bartolomé, and Álamo.

[20] Initially, only a set of intermediate stations were constructed, such as Medio Millar, San Bartolomé, and Fuente Salada, primarily intended as sidetracks.

Throughout its history, the Tharsis railway line had a fleet of several dozen steam locomotives responsible for pulling the freight convoys.