The Fat Vein is one of several precious metal-bearing quartz vein occurrences that were documented during mineral exploration on the Aster claim group in 1987 through 1991. These showings are hosted by metasedimentary rocks (phyllite, quartzite) of the Upper Proterozoic-Paleozoic Snowshoe Group on the east side of Aster Creek, a tributary of the Swift River, about 20 kilometres south-southeast of Barkerville. The Aster showings are several kilometres north of a major cluster of gold quartz vein occurrences that were recognized in the 1800s in the drainages of Little Snowshoe and French Snowshoe creeks (Bulletin 34).

The Fat Vein showing is located on the slope east of Aster Creek, 1.9 kilometres southeast of the creek's confluence with the upper Swift River. It comprises two parallel quartz veins, striking roughly east-west and traced for about 50 and 35 metres, respectively (Assessment Report 17220, Figure 5). The veins dip steeply south, are commonly more than one metre wide, and are locally mineralized with pyrite and galena. A grab sample from the northern vein yielded 1.480 grams per tonne gold and 330.3 grams per tonne silver, and a sample from the southern vein contained 2.415 grams per tonne gold and 268.2 grams per tonne silver. A chip sample across 2.5 metres of sulphide-bearing vein material near the latter grab sample assayed 2.057 grams per tonne gold, 111.4 grams per tonne silver and 1.10 per cent lead (Assessment Report 17220).

On the Aster property, numerous pits, trenches and drifts attest to the high level of previous exploration activity within the general area, but with the exception of a number of early reports, little record exists of the previous exploration. The Aster 1-6 claims were staked in 1987 by V. Guinet as agent for Golden Eye Minerals Ltd. The property was optioned to Sukuma Explorations Ltd. in September 1987 with an initial exploration program consisting of grid establishment (34 kilometres), 20 kilometres of VLF-EM, 1189 soil samples, 78 rock samples, prospecting and geological mapping. In 1988, a field program consisted of 30 kilometres of grid establishment and 1311 soil and 134 rock samples collected. A total of 500 metres of trenching was also completed in 23 trenches with about 500 metres of road constructed to provide access. The 1991 exploration program consisted of 644 soil, 13 silt and 20 rock samples collected.