The collection of a nymph of the fine-lined emerald (Odonata: Corduliidae: Somatochlora filosa) on September 7, 2016 in Sainte-Catherine-de-Hatley, in the Estrie region of Québec, provides the first record of this species for Canada. The breeding habitat of the fine-lined emerald in North America is poorly known, and is reported here for only the second time. The unexpected discovery of a relic population, 575 km north of its previously known range, raises questions concerning the original composition of the odonatological fauna of the hardwood forest subzone of Québec – an ecosystem that has been considerably altered since human colonization of the area and the exploitation of natural resources. In addition, during the present study, the mocha emerald (S. linearis) specimen collected by Léon Provancher in Saint-Hyacinthe in 1877 was authenticated, and the species reinstated to the list of Odonata of Québec. Finally, it is suggested that 3 other rheophilic emerald species could inhabit forest springs and streams in the southern part of the province.