The Pioneer deposit occurs within carbonaceous shale of Upper Triassic age which forms part of the Takla Group. The Takla Group forms part of the Quesnellia Terrane which is bounded to the east by rocks of the Omineca Belt and to the west by the Cache Creek Group.

The mineralization consists mainly of argentiferous galena and sphalerite within a northerly striking northeast dipping quartz vein.

In 1927 four tonnes of ore was mined producing 809 grams of silver, 126 kilograms of lead and 2 kilograms of zinc. Anomalous gold values have also been recorded from the vein.

The area has been explored in conjunction with the nearby Quesnel Quartz (MINFILE 093G 015) occurrence and a complete regional exploration history can be found there.