The Rainy Day (L. 379) occurrences are located near the eastern shore of Henderson Lake, approximately 3 kilometres north of Snug Basin.
The area is underlain by a north trending band of Upper Triassic Vancouver Group, Quatsino Formation limestone. This narrow limestone band is in contact to the west with basalt of the Karmutsen formation (Vancouver Group), and to the east with Lower Jurassic volcanics of the Bonanza Group. The strata is intruded by diorite and granodiorite of the Early to Middle Jurassic Island Plutonic Suite. Mafic dykes are also observed in the area.
Locally, iron and copper minerals are found in skarn at the contact of limestone and basalt in the vicinity of granodiorite. There are four such deposits found on the Rainy Day claim (Lot 379), striking parallel to each other in a north east direction over considerable distances, all within a length of 50 metres of each other.
Ore-body "A" occurs at the immediate contact of limestone and basalt. The mineralization is an association of iron pyrites and some chalcopyrite in garnet and limestone gangue. Little work has been done on this deposit.
Ore-body "B" has filled a vertical fissure in a shear zone in metamorphosed rock. The fissure is 3 metres wide and has been drifted on for 12 metres in solid ore consisting of mainly pyrrhotite with some copper minerals.
Ore-body "C" occurs at the limestone-basalt contact, having a 4 metre width and a vertical dip. The mineralization is chalcopyrite, pyrrhotite and some magnetite in a gangue made up of garnet, epidote, hornblende and crushed limestone. A 20 metre adit was driven parallel to the deposit, with a crosscut to intersect the ore. A winze is sunk for 6 metres in the ore body, near the crosscut, and a drift started along the strike of the deposit. Selected samples show the copper content varying from 4.5 to 16 per cent, but the body as a whole was considered low grade (Minister of Mines Annual Report 1916).
Ore-body "D" is about 12 metres in width and is made up of pyrite, marcasite, some chalcopyrite, hornblende, epidote and garnet. Little work has been done on this deposit.
The area was originally explored in 1899 and 1916. In 1965, Alberni Mines completed a program of geological mapping, geochemical sampling and a ground magnetometer survey. In 1967, Mt. Agnes Mines completed a ground magnetometer survey and five diamond drill holes on the Rainy Day claim. The highest assay yielded 0.94 per cent copper and 5.15 grams per tonne silver over 0.6 metres. Another sample of core (Hole 3) assayed 0.24 per cent copper and 10.3 grams per tonne silver over 2.4 metres of massive pyrite-epidote-garnet (Assessment Report 2856).
In 1969 and 1970, Nootka Explorations completed a program of rock and soil sampling, geological mapping and a ground magnetometer survey on the area as the Henderson property. A sample (H-3) of mineralized skarn from the back drift of the lower portal (Ore-Body “C“) assayed 0.45 per cent copper, 1.04 per cent zinc and 6.9 grams per tonne silver (Assessment Report 2856).
In 1980, the area was prospected by A. Ingelson and L. MacEachern.
In 2007 through 2013, Nahminto Resources completed a program of prospecting, geological mapping, geochemical sampling, a ground magnetometer survey and airborne geophysical surveys on the area as the TJM claims, apart of the Nahmint property.
