In the fullness of August, armadas of clouds sally across the sky. Like ghostly warships, they spew thunder and lightning. Rain pounds the parched prairie and runs in rivulets into arroyos, then into stock tanks where cattle and pronghorns water.

When the daily thunderstorms retreat, a stream of cool air weaves across the high plains. Cattle lift their nostrils, scent the air and go back to grazing. Birds feel a sudden ancient impulse. The hearts of old horses living out their years in stiff-legged retirement beat faster. A ranch wife hanging out the wash feels a cold hand brush her face and thinks about stocking her pantry for winter.

On the range, a man on horseback checks his cattle. The grass is beginning to head out. The wayward breeze that spoke to the cattle, the horses and the woman speaks to the man. He begins to calculate how many pounds his steer yearlings can gain before heavy frost sets in.

The living isn’t easy in Northern Arizona — not for cattle, not for ranchers. Range cows have to travel some for food and water. Depending on range...