The Denver coroner's office identified the man as Robert Seamans of Pueblo, Colo.
"We are deeply saddened to learn of the death of one of our fans," the Rockies said in a statement. "Our thoughts and prayers remain with the family and friends of this young man as we all grieve for his loss."
According to the Denver Police Department's report, witnesses said the 27-year-old Seamans was sliding down a stairway railing in the outfield Rockpile seating section and lost his balance.
He fell more than 20 feet onto a stairwell, suffering head injuries, and was taken to a local hospital.