The Hidden Lake showing is located on the west side of Pooley Island, approximately 65 kilometres north of Bella Bella.

The area is underlain by a north westerly trending contact zone of Triassic age schists to the south west and mid Triassic foliated quartz diorites ot the north east.

Locally, the occurrence is associated with a skarn zone consisting of altered intercalated limestone and garnet schist in contact with quartz diorite. Mineralization consisting of chalcopyrite, pyrite, arsenopyrite, some bornite and an occasional speck of molybdenite occurs in quartz stringers and as disseminations in the skarn. The mineralized zone strikes 120 degrees and dips 60 degrees south. Quartz diorite occupies the footwall while on the hangingwall the zone grades into banded limestone and garnetiferous schist carrying sparser mineralization.

Minor surface work was done on the Hidden Lake property by the Granby Consolidated Mining and Smelting Company in 1928. The owner, W.H. Mault, carried out open cutting totaling 335 metres in 1929. Rainbow Mines conducted 60 metres of trenching and 185 metres of diamond drilling in 1963. In 1966 further trenching and 1200 metres of drilling were done. In 1971, Rainbow Mines changed its name to Greenfields Development Corporation Ltd. In 1995, Verdstone Gold Corporation and Amcorp Industries conducted rock, silt and soil sampling, and trench and drill sampling (2 holes) on the property, which was renamed the Marion claims (including the MAR 7-14 claims). The results indicate the favourable skarn horizon extends to 300 metres in length. An induced polarization survey was recommended to evaluate the down-dip and strike extensions of the mineralized skarn zone.

In 1929 assays gave the following values of 1.37 grams per tonne gold, 13.71 grams per tonne silver and 1.6 per cent copper. In 1971 a sample of the mineralization assayed 99.43 grams per tonne silver and 2.9 per cent copper (National Mineral Inventory Card 103A9 Cu1). In 1995, trench and drill sampling from a mineralized skarn horizon in contact with a foliated biotite granodiorite returned 0.7 per cent copper and 302 parts per billion gold over seven metres with values up to 3.7 per cent copper and greater than 1000 parts per billion gold (Assessment Report 24020).