Etheridge railway line
The railway stations at Mount Surprise, Einasleigh and Forsayth and the route of the Etheridge Railway between Mount Surprise and Forsayth, including surviving railway buildings, rails, sidings, turning forks, loading banks, stone pitched bridges and culverts, stone cuttings, sandboxes, water tank, signage, and signals and points infrastructure, are important surviving evidence of the efforts of the Chillagoe Railway and Mines Company to supply copper ore to its smelters at Chillagoe.
Etheridge railway line
The line has a large number of short timber trestle bridges with concrete abutments, along with a smaller number of medium-size timber trestle bridges, such as the High Bridge in the Delaney Gorge. Longer bridges on the line include those at Junction Creek, Lighthouse Creek, the Einasleigh River and the Copperfield River. Some bridges have one or more concrete piers, and some timbers have been replaced with steel. The bridges without stonework are not of cultural heritage significance, as they were designed to be cheaply replaced if damaged during floods, and the larger bridges have been replaced at various times; for example the Copperfield Bridge was destroyed in 1927, 1980 and 2002.