The herds are thin and weak after trying to survive on dry grass. Ranchers are shipping them out to verdant land in Nebraska, Colorado and elsewhere, hoping to preserve their trademark brands.

The cowboys rose well before dawn, stars still high in the West Texas sky. They strapped on spurs and leather chaps and climbed into their saddles for one last roundup.

They didn’t have to do much to rustle the cattle from the dusty flats about 220 miles west of Dallas. Hundreds of hungry black Angus and Herefords, tired of foraging for scarce, drought-dry grass, came running — drawn by the hope of feed. The cowboys herded the youngest, thinnest and weakest animals into a separate pen, some with ribs and hipbones jutting after weeks without a decent meal.