Abstract This paper reports on a temporary exposure through the flat‐topped segment of the outermost Loch Lomond Readvance moraine near Drymen. The sediment sequence comprises four lithofacies associations that document the deposition of fine‐grained sediments in coalescent subaqueous grounding line fans into Glacial Lake Blane (Blane Valley Laminated Silts). The occurrence of isolated lenses of matrix‐supported gravel (cohesionless debris flows) and evidence of hydrofractiire filling, deformation and faulting in the top of the lake sediments all record the advance of glacier ice over the proximal face of the ice‐contact fans. This confirms previous interpretations of the outermost Loch Lomond Readvance moraine ridge near Drymen as a subaqueous ice‐contact depositional centre that was locally glacitectonically stacked by glacier overriding.