Mining at the Fringes. High-Altitude Prehistoric Copper Mining in the Oberhalbstein Valley (Grisons, Switzerland)

The mining region of Oberhalbstein, to date sparsely studied, has been the subject of archaeological research since 2013. Two mining areas which lie well above the forest line were studied in the summer of 2017. The Avagna-Ochsenalp site includes multi-phased heap features, of which the earliest phase has been dendrochronologically dated to the 11th century BC. In Cotschens, mining traces in an area of approximately 0.1 km2 from an unknown time period have been observed. Here, the flooded mine 1 was studied in more detail. After the cavity had been drained, 66 wood objects were revealed, including mining tools from the 1st century BC. 14C dating further confirms Late Bronze Age and Early to Late Iron Age activity. Stone tools from the adjacent heap also confirm prehistoric on-site ore processing, a unique find so far in the Oberhalbstein region.