Originally this was the spiritual “When the Chariot Comes” about Christ's second coming, but it was adapted as a railroad song in the 1890s.
She'll be comin' 'round the mountain when she comes (when she comes).
She'll be comin' 'round the mountain when she comes (when she comes).
She'll be comin' 'round the mountain,
She'll be comin' 'round the mountain,
She'll be comin' 'round the mountain when she comes (when she comes).