Other sites show more circumstantial evidence of mammoth hunting, such as piled bones bearing butcher marks. Some of these sites are not closely associated with Clovis points. The Dent Site (the first evidence of mammoth-hunting in North America, discovered in 1932) and the Lehner Mammoth-Kill Site, where multiple juvenile and adult mammoths have been found with butcher marks and in association with Clovis points, were once interpreted as the killing of entire herds by Clovis hunters. However, isotope studies have shown that the accumulations represent individual deaths at different seasons of the year, so are not herds killed in single incidents. Many other such assemblages of bones with butcher marks may also represent accumulations over time, so are ambiguous as evidence for large-scale hunting.