Cliff Branch, a former world-class sprinter who was one of the N.F.L.’s top deep threats, winning three Super Bowls in 14 seasons with the Raiders, was found dead on Saturday in a hotel room in Bullhead City, Ariz. He was 71.

The police there, in northwest Arizona, said Branch had died of natural causes. No specific cause was given.

Branch, wiry at 5 feet 11 and 170 pounds but remarkably durable, was one of professional football’s fastest players in his years with the Raiders, 1972 to 1985, first in Oakland, Calif., and later in Los Angeles. He spent his entire N.F.L. career with the team.

“With him it’s not running, it’s flying,” the Raiders owner Al Davis told the columnist Dave Anderson of The New York Times in 1974.