The rocks underlying the Riverside are thought to belong to the Devonian to Permian Knob Hill Group. On the Riverside property the rocks consist of massive altered volcanic flows and fine to coarse-grained tuffs interbedded with gray to green-gray fine-grained quartzites and calcareous siltstones.
Faulting and shearing are evident in all underground workings and could be recognized in some of the scarce outcrops on the surface. Existing mineralized zones or veins were repeatedly faulted and displaced.
Silver and minor gold bearing mineralization consist of flat-lying manto-like zones or veins with pyrite, galena, sphalerite, quartz and varying amounts of calcium carbonate and mariposite. At least four different vein systems have been exposed in the original Riverside workings. The zones or veins vary in width from 20 centimetres to 3.5 metres. The thickest zones are found on the intersection of two major sets of mineral-bearing zones. The first set is steeply dipping at 64 degrees to the south and striking in an east-west direction; and the second is flat lying basin-like structure. Both sets are intensely faulted by a north-south fault system and offset up to 1 metre.
A total of 271 tonnes were mined from the Riverside, from which 264,648 grams of silver, 528 grams of gold, 823 kilograms of zinc and 799 kilograms of lead were recovered.
Drilling by World Cement Industries Inc. returned 3.9 metres at 0.9 gram per tonne gold, 543.8 grams per tonne silver, 1.63 per cent lead and 0.8 per cent zinc and 1.5 metres at 3.8 grams per tonne gold, 1160 grams per tonne silver, 1.63 per cent lead and 0.8 per cent zinc (Property File - Rock Creek Resources (1990-01-01): Property report: Riverside). - Rock Creek Resources (1990-01-01): Property report: Riverside).
In 1898, Big Eddy was Crown granted to B. Perkins and H. Reed. Also other Crown grants such as Commonwealth, Riverside, Brookline, HR and Emilie had already been worked. In 1901, ore for testing was shipped from Riverside. Underground development was ongoing in 1903 and 1905 with some shipments apparently made. In 1907, 61 tonnes were shipped and are on public record. In 1913, four railroad cars of hand-sorted ore were shipped totalling 110 tonnes. The Riverside was granted to Paul Nelson in 1920. In 1921, P. Nelson and Oli Lofstad leased the Riverside claim and drove two crosscuts of 18 metres and 12 metres and 5 metres of raises and shafts. In 1924, extensive sampling was done by Cominco Ltd. A shipment of 7 tonnes is documented for 1933. In 1953, a small amount of exploration work was done in the vicinity of the Riverside property. In 1975 Alerni Mines Ltd. cut 7 exploration trenches totalling 99.3 in on Riverside and Riverside No. 2 Fr. claims. Most of the trenches never reached bedrock. In 1977, some basic exploration work was done on the Riverside and reported by R. S. Verzosa. In 1979, the Kay claims were worked on by Edina International Ltd. In 1979 and 1980, adits 4 and 1 on the Riverside claim were worked by room and pillar method using trackless equipment. Records show that 93 tonnes of ore were mined. In 1982, the Riverside property including Kay 1-7 claims (later Dawn ) was acquired by World Cement Industries Inc. The exploration started with orientation work consisting of VLF-EM, reconnaissance surveys, soil sampling and geological examination of accessible underground workings and surface outcrops. In the spring of 1983, World Cement commenced a surface and underground drilling program. Four holes totalling 299 metres were completed. During 2008 through 2012, Grizzly Discoveries Inc. completed programs of geochemical sampling, geological mapping and ground geophysical surveys on the area as the Greenwood property.
