It is located about 1 km (0.62 mi) southwest of Net Lake and just west of the Ontario Northland Railway in east-central Strathy Township.

Basalt is the primary rock type at Big Dan, forming part of the Arsenic Lake Formation, the site's major geologic feature.

[2] By 1899, O'Connor created test pits at Big Dan, which was followed by a survey for the Ontario Northland Railway route in 1900.

[5] The Temagami Mining and Milling Company operated a concentrating plant and worked two shafts, one open cut and one adit from 1905 to 1908.

After the reduced ore fragments passed through roll crushers, it was then put through three Kriem air separators in the mill.

At the time of exploration, the mine site comprised 190 ha (470 acres), consisting portions of WD271 and six staked claims.

It existed throughout much of the 1970s and 1980s, prohibiting all types of mineral exploration at Big Dan and other mines in Strathy Township.

[5] In 1991, the Supreme Court of Canada decided that the Anishnabai community no longer had aboriginal title to the land they claimed.

[9] However, Big Dan was not explored until 1993 when Falconbridge Limited performed sampling and 10.75 km (6.68 mi) of line cutting and geologic mapping in the area.

[10] Big Dan is situated in the Temagami Greenstone Belt, a 2,736 million year old sequence of metamorphosed igneous and sedimentary rocks that forms part of the much larger Superior craton.

Feldspar-phyric basalt lava flows contain tabular feldspar phenocrysts that range up to 2 cm (0.79 in) in cross section.

[15] At Big Dan, the Arsenic Lake Formation is overlain by a heavily wooded boreal forest.

Minor traces of gold and silver ore with sporadic nickel, copper and zinc values also exist in the shear zone.