rivers have continued to shape the landscape in the post-glacial era. Economy Besides farming, mining and quarrying have been a mainstay of the local economy over centuries. In 2013, a Canadian mining company were allowed to test drill for zinc around Allenheads and Nenthead. They said the region was sitting on a "world-class" deposit of zinc and predicted that a new mine in the area could produce of zinc ore per year. Natural history In the North Pennines are: 40% of the UK's upland hay meadows; 30% of England's upland heathland and 27% of its blanket bog; 80% of England's black grouse (and also breeding short-eared owl, ring ouzel, common snipe and common redshank); 36% of the AONB designated as Sites of Special Scientific Interest; red squirrels, otters and rare arctic alpine plants; 22,000 pairs of breeding waders and one of England's biggest waterfalls – High Force. The area shares a boundary with the Yorkshire Dales National Park in the south and extends as far as the Tyne Valley, just south of Hadrian's Wall in the north. The AONB is notable for rare flora and fauna, including wild alpine plants not found elsewhere in Britain. It is also home to red squirrels and diverse birds of prey. The impressive landscape of the North Pennines – from High Force on the River Tees to the sweeping valley of High Cup Gill above Dufton – are the product of millions of years of geological processes. The worldwide significance of the geology found in the area was recognised in 2003 when the AONB became Britain's first European Geopark. A year later the area become one of the founding members of the UNESCO-assisted Global Geopark family and in 2015 it was accorded official status as a UNESCO Global Geopark. Geoparks are areas with outstanding geological heritage where this is being used to support sustainable development. Another of the North Pennines' oddities is that it is home to England's only named wind, the Helm Wind. It has caught out many walkers traversing the plateaux around Cross Fell, the Eden Valley fellside, and the valleys between Alston and Dufton. Recreation One of the many walking routes in the North Pennines is Isaac's Tea Trail, a circular route of around the area, running from Ninebanks via Allendale, Nenthead and Alston. In addition to this, a large section of the Pennine Way falls in the AONB, including one