Geological Timeline By Clair_Uytterhagen 50,000 BCE Eon: Phanerozoic Era: Cenozoic Period: Quaternary Epoch: Pleistocene Bison come to North America 20,000 BCE Eon: Phanerozoic Era: Cenozoic Period: Quaternary Epoch: Pleistocene Humans come to North America 10,000 BCE Eon: Phanerozoic Era: Cenozoic Period: Quaternary Epoch: Holocene the beginning of the Holocene. Origin of the Prairies
