Snowshoe hare virus of the California encephalitis group of arboviruses was isolated from female Aedes implicatus Vockeroth reared from larvae collected in the Southern edge of the mixed-wood forest near Macdowall, Saskatchewan, Canada. This is the first reported isolation of an arbovirus from A. implicatus and suggests that transovarial transmission contributes to the natural maintenance of snowshoe hare virus in Saskatchewan. The advantages of transovarial transmission in the mosquito for survival of a virus whose hosts alternate between a univoltine Aedes and rodents or lagomorphs at northern latitudes are briefly discussed. An infection cycle, involving an Aedes that takes only one blood meal during its lifetime, is suggested.