At the end of the last Ice Age, American Indians arrived in this region twelve thousand to fifteen thousand years ago. As the earth warmed and the ice melted, sea levels rose dramatically, and by five thousand years ago ancient lands and rivers once used by the earliest Indians were buried beneath the rising waters of the Chesapeake Bay and its rivers. As the climate stabilized, evergreen trees were replaced by hardwoods that provided habitat for deer, elk, and smaller game, while fish migrated up the tributaries of the Chesapeake Bay. The first Indian people came to Mount Calvert about eight thousand years ago during the Archaic Period, from seventy-five hundred to one thousand B.C. These hunters and gatherers thrived on the region's plants and animals. Archaeologists have recovered thousands of Archaic Period Indian artifacts at Mount Calvert, including spear points, knives, and the remains of stone cooking hearths, which provide insight into the lives of the people who lived here before Europeans and Africans arrived.