The Bonanza showings are located on the western slope of Mount Gardner on Bowen Island, approximately 8.5 kilometres south east of Gibson. The showings were originally discovered in the 1890’s and two adits were driven in 1905. No records of any ore shipments exist. In 2004, two 2- post mineral claims were staked to cover the occurrence by J. Laird.

Regionally, the area is underlain by metavolcanic and metasedimentary rocks of the pre-Jurassic Bowen Island Group. These rocks consist mainly of dark green andesites, white to light grey and purple cherty tuffs with minor quartzite, porphyry and limestone. Dioritic rocks of the Jurassic to Tertiary Coast Plutonic Complex occupy the southern portion of the area.

The main adit was located at about the 360 metre level and followed a well mineralized quartz vein up to 1 metre wide for 90 metres. The vein contains pyrite, sphalerite, galena, arsenopyrite and chalcopyrite in a gangue of quartz and wall rock fragments. This occurs in a zone of fractured or sheared volcanics and cherty sediments, near a minor diorite intrusion. The lower adit, about 90 metres long, is reported to have contained chalcopyrite and pyrrhotite in sheared Bowen Island Group volcanic rocks.

In 1988, three grab samples returned values up to 10.22 grams per tonne gold, 45.33 grams per tonne silver, 15.81 per cent lead, 10.4 per cent zinc, 7.41 per cent arsenic, 0.12 per cent copper and 0.05 per cent antimony (Property File - Laird, J. (2004): Golden dreams and broken hopes - Bowen Island). At this time, a vein sample was submitted for lead-dating and returned an age of Lower Cretaceous, ~100 m.y., similar to that of the Britannia Mine (092GNW003).