Abstract
SUMMARY: A radiocarbon‐dated pollen diagram from Valley Bog, situated in the upper reaches of Tees‐dale, is discussed. It provides evidence for a late alder expansion and the possibility of Mesolithic human activity on the Moor House National Nature Reserve. When compared with pollen diagrams from lowland County Durham there appears to be a delay in the elm decline at the high altitude. The elm decline is followed by a phase of Bronze Age deforestation which precedes a similar but more prolonged and pronounced Iron Age clearance.