The Twin-1 occurrence is 1.5 kilometres northwest of Upper Twin Lake with access approximately 5 kilometres by paved road southwest from Highway 3A to the public boat launch site at the west end of Lower Twin Lake, then another 3 kilometres westerly by dirt road.

The showing is underlain by the Olalla Rhyolite of the Miocene-Pliocene Chilcotin Group in the Twin Lake area in the western part of the Penticton Tertiary outlier. The rocks consist mostly of hydrothermally altered rhyolite breccia capped by a smaller area of fresh rhyolite obsidian. The obsidian with pozzolan and some perlite attributes is an apparent resource of several million tonnes underlying most of the central part of the claim. The altered rhyolite tuff breccia, adjacent to the obsidian, covers a much larger area but represents a less well defined mineral potential than the obsidian.

An obsidian ‘dome’ measuring approximately 300 by 500 metres represents an estimated 6 million tonnes of volcanic glass (Assessment Report 27222). Chemical data shows that the glass contains 4.28 per cent structural water. This is somewhat higher than the average water content for obsidian but within the usual range for perlite, although preliminary tests show no expansion properties typical of perlite when samples are heated. Nevertheless, the obsidian remains a potential pozzolan resource. It is expected that when this material is mechanically crushed and mixed with lime, the glassy fragments and fine powder would tend to react when moistened to form cementing minerals.

In 2002, a geological evaluation was performed on behalf of owners/operators B.N. Church and D.R. Haughton.