The Mesolithic Period
The history of Latvia between 9000 BC and 3001 BC
Archaeologists and historians consider that the first inhabitants of the Baltic lands, who began to populate them immediately after the Ice Age, (about 9,000 B.C.), were hunters, but the forms of culture of the so-called Stone Age were as yet too primitive to allow of conclusions about the ethnic relations of this people.
Reference: Latvians.com