The Stone Age is itself divided into the Old Stone Age (Palaeolithic), Middle Stone Age (Mesolithic) and New Stone Age (Neolithic).
The earliest known occupation sites in the North Pennines date from about 10,000 years ago, during the Mesolithic. Mesolithic people, often referred to as ‘hunters and gatherers’ lived a nomadic lifestyle, moving around the landscape to exploit available natural resources in a manner probably not greatly different form that of many nineteenth-century Native American communities. They have left few clues as to their presence in the North Pennines other than their flint tools and weapons, recovered from the surface of ploughed fields and in upland locations throughout Weardale, Teesdale and elsewhere. Most of the flint, which does not occur naturally anywhere in the North Pennines, seems to have been imported from the Yorkshire and Lincolnshire Wolds.
The extensive peat blanketing the high hills is probably in part the result of Mesolithic activity. Once covered in scrub woodland, upland areas were burnt to provide temporary grassland clearings for wild herds and encourage the growth of hazel (hazel nuts, gathered in the autumn, provided much needed nutrition during the winter months, when other food sources were in short supply). After a year or two, these clearings would revert to scrub woodland, but as the climate became cooler and wetter from about 8,000BC woodland on the thin upland soils found it harder to regenerate. As more and more woodland was lost, the hills gradually became clothed in peat and heather, although the better soils in the valleys continued to support dense woodland.
Between about 6,000 and 4,300 years ago, during the Neolithic (New Stone Age) communities throughout the North Pennines gradually adopted farming alongside long-established practices of hunting, fishing and gathering. Evidence of early farming communities here is sparse: no settlements from the period have been excavated, but palaeoenvironmental evidence suggests some lowland areas were being cleared of trees to create temporary agricultural clearings. As with the Mesolithic, evidence for Neolithic communities here exists principally in the form of their stone tools, including characteristic polished stone axes and beautiful leaf-shaped flint arrowheads.
In many parts of Britain, Neolithic communities built great tombs and temples: the great Cumbrian stone circle of Long Meg and her Daughters, amongst the most important Neolithic sites of northern England, lies on the western fringe of the AONB in the Eden Valley. On an altogether more local scale, several little stone circles, like the fine example at Lunehead, probably stood within and around the AONB in late Neolithic/early Bronze Age times. These may have played a similar role to the parish church in later times, providing the focus for communal gatherings and ceremonies.