4000-1800 years ago (2000 BC - 200 AD)
Lifeway: Nomadic hunters and gatherers
Dwellings: Caves and rockshelters
Diet: Bighorn sheet, small game, seeds and nuts
Special traits: Focus on Bighorn Sheep
Challenge: Disappearance of water, plants, sheep.
Response; Greater effort to take sheep; rituals and tools refined
Result: They did not adjust to changing environment. Gypsum Culture died out