was dry and mostly desert. The people living there at the time survived as hunter-gatherers. Farther south was Mesoamerica, where early people survived by farming.
Puzzling..to the North were green forests and fertile valleys to the northwest. To the south was greenery and water.
Yet they stayed to pick up rocks?
Either not real smart or, more likely, the analysis is lacking.
Maybe the places in the south were run by liberals?