Bowie, TexasA black bull charges out the chute, and two riders give chase. The cowboy in front lassos the neck at a full gallop, slowing the bull just enough for rodeo heeler Whitney Monroe to maneuver her buckskin gelding into position and snare one of the bull’s hind legs with her rope, then release it with a snap of her wrist.

Dazzling as the riders are, the trained eyes of would-be buyers watching from the stands this July day are on the horses, tracking their agility, speed, and instinct. On her next turn in the outdoor arena, Monroe, 33, a former rodeo queen who jokes that she was “probably conceived on a horse,” guides her mount between a triangle of barrels. Whipping