Salter's Meridian 1856
While laying out a meridian line (a north-south survey line) in 1856, provincial land surveyor Albert Salter observed severe compass needle deflections some five kilometres north of here. Alexander Murray, assistant provincial geologist, examined the area and reported "the presence of an immense mass of magnetic trap". Analysis of rock samples revealed nickel, copper and iron. This was the first indications of the Sudbury region's mineral wealth, but it aroused no interest at the time because the site was so remote. In 1886 prospector Henry Ranger rediscovered the deposit and in 1900 the Canadian Copper Company (later International Nickel) began working the claim. It became the Creighton Mine, one of the world's leading nickel producers.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.