The distribution of projectile points over broad geographic areas yields important insights about Palaeoindian settlement pattern and history. While traditionally viewed as a Great Plains adaptation, the data show that fluted points are far more common in Eastern North America. These artefacts are not evenly spread across the landscape, furthermore, but occur in distinct concentrations. Within some of these areas distinct cultural traditions quickly emerged, something that appears tied to the sudden onset of the Younger Dryas.