The Argo is underlain by granodiorite of the Greenwood Pluton and greenstone of the Upper Paleozoic Knob Hill Group. Quartz veins, varying from 5 to 90 centimetres wide, striking about 25 degrees northeast, occur in the rocks. Low grade copper ore was found in the Argo tunnel, but was not mined at that time. Pyrite, galena, sphalerite and chalcopyrite are associated with gold and silver
A vein was struck on the Argo claim in 1914 by the Argo Mining and Tunnel Company Limited. By 1917 the tunnel had been driven a distance of about 550 metres at a depth of about 183 metres from the surface. The tunnel was commenced in, or just prior to, 1909 by Olie Lofstad, president of the company, in order to strike the adjacent Starveout (082ESE008) and Barbara (082ESE007) veins.
It was reported in 1928 that the Hercules Consolidated Mining, Smelting, and Power Corporation, Limited had cleaned out the old Argo tunnel