The Wilcox past-producing mine is located on the north side of Ymir Creek, approximately 30 kilometres southeast of Nelson.

The area is underlain by granodiorite of the Middle Jurassic Nelson Batholith. Northeast-trending roof pendants of Lower Jurassic Ymir Group metasediments occur within the batholith.

The Wilcox occurrence consists of a number of parallel quartz veins, emplaced along minor shears, striking 075 to 080 degrees and dipping 70 to 90 degrees north. The veins are hosted by greenish-grey, fine- to coarse-grained granitic rocks. The three major veins are the Fourth of July, Little Willcock and Willcock veins, all of which crosscut the granitic foliation. To the west, the veins terminate against a roof pendant of schists. Disseminated mineralization continues into the granite for up to 4.9 metres and spreads into ‘T’- or ‘L’-shaped zones. The massive white bull quartz veins contain up to 30 per cent sulphides consisting of irregular masses and disseminations of pyrite, pyrrhotite, minor sphalerite, galena and arsenopyrite. Free gold is common. High-grade material occurs in the hangingwall side above the no. 1 tunnel and the ore generally occurs in tabular shoots with an east pitch. Although the vein is on average 45 centimetres wide, oreshoots may be up to 2 metres wide and 10 to 20 metres long. Wallrocks are locally silicified and may contain ore-grade disseminated sulphides. In many places a fault gouge of decomposed feldspar accompanies the ore.

The two Fourth of July veins, extending onto the Willcock claim, strike 95 to 115 degrees and dip 50 to 55 degrees north. These veins are 0.10 to 0.20 metre wide and are separated by 20 metres of foliated granodiorite. Mineralization consists of minor disseminations and stringers of pyrite and occasional clusters of galena.

In 1926, two samples taken from the bottom of the shaft, 10.5 metres below the no. 3 level and in the 141 intermediate level, assayed 15.0 and 33.5 grams per tonne gold, 61.6 and 133.4 grams per tonne silver with trace and 9.6 per cent lead over 39 and 57 centimetres, respectively (Property File - O.D. Frith [1926-05-07]: Report of Preliminary Examination of the Wilcox Mine).

In 1985, a chip sample (#J-07) assayed 27.8 grams per tonne gold, 561.4 grams per tonne silver, 1.95 per cent lead and 0.124 per cent zinc (Assessment Report 14555).

The area has been explored since the late 1890s, with production being recorded for the periods of 1901 through 1905, 1910, 1911 and 1931 through 1943, totalling 14 555 tonnes yielding 241 982 grams of gold, 526 635 grams of silver, 98 224 kilograms of lead and 30 649 kilograms of zinc. Underground exploration consisted of five tunnel levels and three main levels, comprising 1829 metres of development.

In 1981, the area was prospected by A. Ingelson. In 1984, Arizako Mines soil sampled the area. In 1985, Goldrich Resources completed a program of rock and soil sampling.