A horse and rider complete an introductory lap before a rodeo show in a muddy Tucson, Arizona, arena.

Rodeo evolved from the often dangerous tactics cowboys used to break horses and to catch and brand cattle. In most professional rodeo shows, riders compete in seven events: saddle bronc riding, bareback riding, bull riding, calf roping, steer roping, team roping, and steer wresting.

(Photo shot on assignment for, but not published in, “Rodeo: Behind the Chutes,” September 1999, National Geographic magazine)