The Breccia showing is located approximately 2 kilometres west of Salmo and 500 metres north of Erie Lake.

Regionally, the area is underlain by Early Jurassic Rossland Group rocks intruded by phases of the Middle Jurassic Nelson Batholithic Suite. The Rossland Group is made up of sequences of fine to coarse sediments of the Archibald Formation, volcanics of the Elise Formation and fine-grained clastic rocks of the Hall Formation.

Locally, the area is underlain by Archibald and Elise Formation metasediments and metavolcanics, intruded in some areas by the Middle Jurassic Bonnington Batholith and a smaller biotite-granodiorite intrusion of Middle Jurassic stock.

Mineralization occurs in the argillite and siltstone of the Archibald Formation as galena, sphalerite, pyrite and chalcopyrite as disseminations in quartz stringers and in the matrix of the brecciated intrusive.

The original claims on the property were Crown-granted between 1898 and 1904; several adits, pits and shafts were dug during this period. Two cat trenches were also dug on the property sometime before 1988; however, no documentation of this work is available.

In 1988, R. Bourdon staked the Shamrock property.

In 1990, R. Bourdon and C. Pittman completed rock sampling and a reconnaissance magnetometer survey. Highlights of the sampling program include sample 16342, which assayed 2.07 per cent lead, 3.73 per cent zinc, 0.25 per cent copper and 44.6 grams per tonne silver (Assessment Report 20208).

In 2007, the Sadarsa claims (which encompass the Shamrock showing) were staked by D. Lavoie.

In 2008, prospector Tom Kennedy completed a two-grid soil geochemistry survey.

In 2011, Tom Kennedy and Trygve Hoy conducted a program of rock grab sampling, geological mapping and prospecting. Highlights include sample TK11-004, which assayed 9.4 grams per tonne silver, 0.2255 per cent lead, 0.2486 per cent copper and 0.4655 per cent zinc (Assessment Report 32482).