The Helen occurrence is underlain by highly metamorphosed greenstones and quartzites of the Upper Paleozoic Knob Hill Group. A quartz vein, striking west and dipping 60 degrees south, varying from a fraction of a centimetre to 60 centimetres wide, occurs along a well defined fissure in the metasediments. Pyrite, galena, sphalerite and possibly tetrahedrite are associated.

The Helen vein has been traced on surface for several hundred feet by opencuts. Uphill and to the northeast, other quartz veins have been indicated by shallow shafts and cuts. Drifts on the Helen had been run 35 metres to the southeast and 43 metres to the northwest from the bottom of the west shaft. An 8 inch sample across the vein, 1.8 metres from the north drift, assayed 1.37 grams per tonne gold and 480 grams per tonne silver (Minister of Mines Annual Report 1934, page D6).

Two shafts were initially begun on the Helen in 1894. Development seems to have been continuous from 1904 to 1906. Seventy-two tonnes were reported shipped in 1905 and 15 tonnes in 1906. In 1905 alone, the Helen Mining Company, of Chicago, did 84 metres of sinking and raising, and more than 122 metres of cross-cutting and drifting and the shaft was down 64 metres. Records do not indicate commodity recovery for 1905. In 1921, a lease was taken on the property by Ola Lofstad and 2 adits were driven at lower elevations than the outcrop and a small quartz vein was developed. Lofstad shipped 18 tonnes in 1925. Records under the name of Robert Lee indicate that a further 9 tonnes were mined in 1940. Production records (not including 1905) indicate that a total of 42 tonnes were mined from which 6096 grams of silver, 186 grams of gold, 1861 kilograms of lead and 117 kilograms of lead were recovered.