On October 20 , 2009 , with the death of retired U.S. Senator Clifford P. Hansen , a Wyoming Republican , Byrd became the oldest living former senator until his death at the age of 98 .
On October 20 , 2009 , with the death of retired U.S. Senator Clifford P. Hansen , Byrd became the oldest living former senator until his death in 2013 at the age of 98 .