Lake Waiau provided drinking water for the workers. Native chiefs would also dip the umbilical cords of newborn babies in its water, to give them the strength of the mountain. Use of the quarry declined between this period and contact with Americans and Europeans. As part of the ritual associated with quarrying, the workers erected shrines to their gods; these and other quarry artifacts remain at the sites, most of which lie within what is now the Mauna Kea Ice Age Reserve.