The Pioneer mine has been worked on 27 levels to a depth of 1,020 metres from 5 shafts. Most of the production came out of the main vein until 1944 and the 27 vein until 1960. The veins are hosted mainly in Pioneer Formation greenstone of the Upper Triassic Cadwallader Group and in sodic granite, either associated with the Permian Bralorne Igneous Complex, or the Cretaceous to Tertiary Bendor pluton. The soda granite extends as a narrow tongue along the northwest border of the Bralorne diorite, which hosts the Bralorne deposits (092JNE001) directly north. At the Pioneer mine, the diorite pinches out between soda granite and the serpentinite in the Cadwallader break. For more age data see (092JNE001).

The main vein strikes west-northwest and dips steeply north in a reverse fault. It is strongly ribboned, averages 1 metre in width and splits into a composite system with numerous loops, branches and crossfaulting. There are 4 main ore shoots which have been worked to 1074 metres depth, along dip and for 1140 metres along strike. The 27 vein occupies a tension fracture, branching off the hanging wall side of the main vein. It strikes northeast and dips moderately northwest, averaging 30 to 150 centimetres in width but attaining up to 6 metres in width. The 27 Vein has been followed along strike for 48 metres and is distinctive from the main vein in that the quartz is massive bull quartz rather than ribboned.

The Countless vein is exposed on the surface on the Pioneer property, and passes north into the Bralorne property where it is correlated with the Coronation vein (092JNE007).

The Pioneer veins are composed of mainly quartz gangue with fractures filled with calcite and ankerite. Small shoots of scheelite occur in the main vein and tourmaline is said to occur in cavities in the 27 Vein. The quartz ribbons separate streaks containing chlorite, sericite, mariposite, gouge sulphides and gold. The principal sulphides, arsenopyrite and pyrite, occur as disseminations in massive quartz or in the ribbon partings. Massive arsenopyrite is often associated with free gold. Other sulphides include sphalerite, galena, chalcopyrite, pyrrhotite, marcasite and stibnite. Wallrocks are intensely altered and contain quartz, sericite, mariposite, kaolin, alunite, calcite and arsenopyrite. Low grades of gold are sometimes found in the wallrocks.

An assay was reported as 24 grams per tonne gold at the 25 level (600 metre long drift, average over 412 metres by 15 metres width) (Property File - Report by J.S. Stevenson, 1947).

The Pioneer property was consolidated with Bralorne Mines in 1959.

Proven and possible reserves of the Countless vein are 110,000 tonnes grading 17.1 grams per tonne gold (Information Circular 1996-1, page 17). Bralorne Pioneer Gold Mines Ltd. and International Avino Mines Ltd. hold the property.