Federal police were unable to persuade the woman not to jump from the pedestrian walkway overlooking the dam late Saturday, U.S. Bureau of Reclamation spokeswoman Rose Davis told The Associated Press.
The woman's body was discovered downstream Sunday morning by kayakers on the Colorado River, almost 900 feet below the span. She was turned over to National Park police at Willow Beach, Ariz.
The woman's identity wasn't immediately made public by the Clark County coroner office in Las Vegas, pending notification of relatives.
Davis called the suicide the first that federal officials know of at the Michael O'Callaghan-Pat Tillman Memorial Bridge, which carries U.S. Highway 93 between Las Vegas and Phoenix.
The $240 million span, with twin concrete arches measuring 1,060 feet, crosses Black Canyon just downstream from Hoover Dam.
It is the longest bridge of its kind in the Western hemisphere, according to federal transportation officials, and the second tallest bridge in the United States after the Royal Gorge Bridge in Colorado.
The bridge is named for former Nevada Gov. Mike O'Callaghan and Pat Tillman, the former NFL player who quit the Arizona Cardinals to join the Army Rangers and died in Afghanistan under friendly fire.
