 In 1969, Rosario discovered the Pueblo Viejo oxide gold deposit in the Dominican Republic, which became at startup in 1975 one of the largest gold mines in the Americas, producing more than 400,000 ounces per year.Also in 1969, Rosario discovered Alberta's prolific Dunvegan Gas Field, up to that time the largest gas field found in Canada.In the 1960s, the company acquired an industrial minerals business, producing granite and limestone in Florida.