In the Early Archaic period (11,000 – 6,500 BCE), the presence of discoidal stones at sites attributed to the first coastal communities suggests a connection or underlying cultural similarity with other relatively contemporary South American populations, such as the PaleoIndian groups of Patagonia and the Las Vegas complex in Ecuador. In addition, the similarities between certain stone instruments used by these northern peoples and those used by hunting groups on the eastern side of the Andes points to possible relations between the two, established perhaps during the occasional journeys that both groups made across the mountains in search of particular resources. About half way through the Middle Archaic Period (6,500 to 2,000 BCE), aridity increased in the region and groups living in the Argentine foothills, relatives of the Los Morrillos culture, began to visit the Pacific coast more frequently in search of more stable food sources. In the early part of the Late Archaic (2,000 BCE –0) the climate and humidity stabilized, enabling more permanent, year-round occupation of the coastal region, which led to population growth here. At the same time, the coastal hunter-gatherers in the northern part of this territory established ties with similar groups on the Norte Grande coast, reaching as far north as Taltal and Antofagasta. This long cultural period came to a close in the first few centuries of the present era, when the production of food radically changed the way of life of these peoples, leading to the development of the El Molle Culture.