Early Human Migration By summer.arellano Period: 200,000 BCE to 13,000 BCE Early Human Migration 20,000 BCE Ice Age 17,000 BCE De-Glaciation of Alaskan Coastline “We now know that the glaciers may have blocked the coastal route for a few thousand years. However, these glaciers retreated around 17,000 years ago, which opened the door for human migration along the coast.” (Smithsonian, Lesnek)
