The Zag 1 occurrence is located north of Eureka Creek, approximately 2.3 kilometres northwest of its junction with Barnes Creek and at an elevation of approximately 1470 metres.

The area is underlain by mudstone, siltstone, shale and fine clastic sedimentary rocks of the Devonian to Triassic Harper Ranch and (?) Nicola groups. These have been intruded by granodioritic rocks of the Cretaceous Whatshan Batholith.

Locally, a porphyritic diorite hosts quartz veining with pyrite and pyrrhotite. In 1983, three rock samples (ND16, 19 and 22) yielded from 11.5 to 38.0 grams per tonne silver with trace gold (Assessment Report 12338).

In 1983, Golden Porphyrite Ltd. conducted a limited geochemical and prospecting survey on the area as the Zag 1-2 claims.