The Railway occurrence consists of several small zones located near the summit of Thatue Mountain, about 13 kilometres east-northeast of the village of Iskut.

The area of Thatue Mountain is underlain primarily by Devonian-Permian Stikine assemblage phyllite to phyllitic greenstone. East of the summit, a northeast-trending fault separates these phyllitic rocks from Lower-Middle Jurassic Hazelton Group rocks which may include tuffaceous wacke, siltstone, shale, chert pebble conglomerate, sandstone and plagioclase porphyry flows, breccia and tuff. The Railway pluton is largely confined to several fault-bound slices north, west and south of Thatue Mountain. The pluton is described as a biotite-augite meta-monzodiorite (Geological Survey of Canada Open File 1080).

The Discovery zone is located just west of the Thatue Mountain summit. Exposed in a hand trench is a 40 centimetre wide quartz-carbonate vein with up to 2 per cent chalcopyrite, and an adjacent 40-50 centimetre wide breccia zone with quartz, carbonate, pyrite and chalcopyrite. A selected grab sample assayed 1 per cent copper and 0.05 gram per tonne gold (Assessment Report 21760). Chip samples yielded much lower values. In 2010, sampling (TJR 1005) of well mineralized material with semimassive chalcopyrite, pyrite, abundant malachite and a dark sulphide (tetrahedrite?) yielded 9.35 per cent copper, 52.6 grams per tonne silver, 294 parts per billion gold and 154 parts per billion platinum (Assessment Report 31676).

In 2010, the Ptarmigan showing was discovered north of the main Discovery showing and is made up of a brecciated quartz-carbonate vein with chalcopyrite and secondary malachite, bornite and chalcocite. Results from rock samples yielded 2.78 per cent copper from sample TJR 1022 and 683 ppb gold from sample TJR 1023 (Assessment Report 31676).

The Porphyry zone consists of several outcrops of monzodiorite and phyllite in a 20 square metre area, located about 1 kilometre east-southeast of Thatue Mountain peak. Trace to 2 per cent very fine pyrite and trace to 3 per cent chalcopyrite are associated with narrow quartz-carbonate veinlets and breccia matrix material.

The Breccia zone is within a few hundred metres southeast of the Porphyry zone. Weakly mineralized maroon tuff occurs in an area about 100 metres wide. It contains 1 to 2 per cent chalcopyrite with minor malachite and bornite in association with quartz-carbonate fracture and breccia fillings.

The "Altered Toodoggone Volcanic" zone occurs about 1.2 kilometres to the southwest of Breccia zone. It is reported to be a green and maroon tuff breccia with disseminated fine-grained chalcopyrite.

West Pride Industries first prospected the area in 1990. Hyder Gold Inc. optioned the property and did follow-up geochemical work in 1991.

In 2010, T. Johnson and B. Jacobson from Ranex Exploration carried out a prospecting program and 29 samples were taken and sent for analysis.