The Treasure Mountain region is underlain by northwest striking, moderate to steeply southwest dipping volcanic and sedimentary rocks of the Lower-Middle Jurassic Dewdney Creek Formation (Ladner Group) and Lower-Upper Cretaceous Pasayten Group, intruded by numerous dikes and sills. The Dewdney Creek Formation comprises volcanic rocks and a minor amount of sediments and consists of tuff, breccia and agglomerate with interbedded argillite and conglomerate. The Dewdney Creek Formation is considerably altered; pyrite is commonly present and many outcrops are rusty. The Pasayten Group includes predominantly arkose, argillite and conglomerate. Locally, the two sequences are separated by a northwest striking, northeast dipping fault, but in large part are conformable.

Several faults occur. Two faults cross the southwest part of the region and strike east and dip steeply south, but one splay of one fault dips north. The more northerly of these two faults, the Indiana fault, hosts the Blue Bell (092HSW020) and possibly the Indiana (092HSW022) and Summit (092HSW023) occurrences. The southern fault, the Queen Bess fault, hosts the Queen Bess occurrence. These two faults diverge to the west from the Treasure Mountain fault, and contain subparallel splays separated by shattered rock. The Queen Bess fault splits into two branches that diverge toward the west.

Mineral occurrences in the area are hosted in the Treasure Mountain fault and in and near subsidiary faults, and comprise one or more quartz-carbonate veins or stringers that branch and split and vary considerably in width and attitude (see Treasure Mountain, 092HSW016).

The Queen Bess occurrence is underlain by north-northwest striking, southwest dipping Dewdney Creek Formation breccia, agglomerate, thinly bedded argillite and tuff. The Queen Bess fault strikes 065 degrees and dips 65 degrees northwest through the area. A feldspar porphyry dike, 0.9 metre wide, has intruded along the footwall of the fault; wallrock is pyritic. An adit explores the fault zone which consists of several slips and also contains a quartz vein, 15 centimetres wide, mineralized with pyrite, sphalerite and argentiferous galena and pyrrhotite. Calcite is also present as gangue. A sample across 25 centimetres of the east face of the drift assayed 260.52 grams per tonne silver, 3.9 per cent lead and 15.2 per cent zinc (Minister of Mines Annual Report 1952, page A132).

In the east, the fault zone is exposed by opencuts where several parallel quartz stringer veins form a zone 0.9 metre wide. Minor amounts of sphalerite, galena and pyrite are present. The quartz veins are stained dark by a coating of manganese oxides. Epidote and sericite occur disseminated throughout the veins and along vein selvages. A recent grab sample from an opencut above the lower adit assayed 129.23 grams per tonne silver, 4.02 per cent lead, 3.94 per cent zinc, 0.02 per cent copper and 0.03 gram per tonne gold (Dewonck, 1987).

Towards the west, the fault zone splits and is less mineralized. This fault extends onto the Blue Bell occurrence (092HSW020) to the east.

Past work consisted of some underground development.