A 5 m sequence of organic-rich sediments (ca. 13 000 years BP to ca. 4500 BP) from a drained glacial kettle pond near Brampton, Ontario, has yielded a rich and varied assemblage of coleopteran fossils. This paper discusses the beetles recovered from the basal 1 m of the section (ca. 13 000 to 12 500 BP), which represent the earliest phase of deposition in the kettle, prior to the final melt-out of underlying ice. The species are typical of northern boreal or tree-line habitats today. They illustrate that during this time the landscape was predominantly open ground, with herb and shrub vegetation. Individual trees or isolated clumps of conifers were nearby, as suggested by the presence of scolytids (bark beetles). The mean July temperature was in the range from 12.5 to 15 °C, indicating that the lack of trees is a lag effect in colonization, perhaps due to unsuitable substrate conditions rather than to an unfavourable climate.