Graptolites have been recovered from limestones at Lake Waswanipi, Québec, in an Ordovician outlier on the Precambrian Shield. These limestones were previously interpreted as Wilderness, Trenton, or Richmond in age. They are now assigned a middle Climacograptus spiniferus to C. pygmaeus Zone age, dating the transgression over this part of the shield. Associated megafossils, though poorly preserved, are described. Correlations are made with other graptolite-bearing carbonates in eastern and central North America.