Monte Verde I (MV-I) is located under an outwash plain, which formed during the last glaciation. It is not directly below MV-II. It was first concluded to be a site of human occupation because of three clay-lined burned areas and 26 stones, 13 of which may have been modified by humans. In 2013, Dillehay and his team returned to perform another excavation at Monte Verde due to the inadequate previous excavations. In 2015, Monte Verde I was re-dated to around 18,500 to 14,500 BP. Charcoal remains, charred animal bone fragments and, several lithic artifacts, about 34% of which were derived from non-local sources, were discovered. The older end of this range is controversial, however, as it is based on putative lithic tools which some have suggested are instead naturally occurring objects.