The first inhabitants of Connecticut, known as Paleo-Indians, arrived more than 10,000 years ago after the melting of the last glacier covering New England. The earliest dated human occupation site was located on the banks of the Shepaug River in Washington Depot. 

Paleo-Indian sites have been found in major river and stream valleys, in rockshelters, and on the margins of what were once glacial lakes. It is probable that Paleo-Indians also lived along the shore.

The total Indian population was very small and that short-term camps were the rule. Since one locale could not serve all of their needs for a full year, they had to move frequently to take advantage of seasonally abundant resources. Fewer than twenty people stayed here for less than a month before moving, never to return to the same camp.

Connecticut Paleo-Indians obtained much of their chert (a high quality stone used for making tools) adjacent to fast-moving streams. Few implements were made of local quartz, which tends to shatter unpredictably when flaked. Coarse-grained igneous rocks were used as crude hammerstones. The tools they constructed were used for the hideworking, woodworking, plant processing, hunting, boneworking, and tool manufacturing .

Although hunting with spears and javelins to obtain meat, hides, bones, and sinew was undoubtedly very important, fishing and gathering of wild plants also took place.