Paleoindian Period, 16,000–10,000 years ago
When Native Americans first arrived in Pennsylvania, glaciers covered the northern part of the commonwealth. Towards the end of this period, temperatures averaged ten degrees colder than today. Vegetation was generally an open spruce forest with a few broad-leafed trees, such as oaks, along major streams and rivers. Hunting a variety of large and small game and fishing probably provided at least 60 percent of the diet. Spear points, knives and choppers for butchering animals and scrapers for cleaning hides are the most common tools. In the northern part of the state there is evidence of the hunting of migratory caribou. In the southern part of state, general foraging in the form of gathering seeds, nuts, berries, roots and fishing was more common. People generally lived in small family bands of less than four families (fifteen men, women and children). Periodically, they may have met to form larger groups when hunting caribou. Although the overall quantity of food in this environment was low, the human population was also small, allowing them their choice of foods which were the easiest to collect.
Read more about the Paleoindian Period diet at This Week in Pennsylvania Archaeology.