cows

The trade, she recalls, left "beaded girls in the dormitories and bare-horned cows in the meadows".

His parents were too poor to buy shoes for their children, so when he was a boy Cruz left school to work alongside his father, caring for cows and crops.

He showed us the dozens of cows he keeps near his home, and the hay he stores to feed them.

"It feeds into this new narrative that cattle were perhaps important as beasts of burden," she said, adding cows could be used to carry more lightweight kit.

Shasta and the Sierra Nevada, rivers course down to the valley floor, to vast fields of rice, endless orchards of peaches and golden, rolling grassland full of more cows than people.