The Contra Costa County Board of Supervisors voted against the request to rename the peak, Mt. Reagan.
They also rejected a follow-up proposal to name it Mt. John Muir.
An Oakley man petitioned to have the name changed, because "diablo" is the Spanish word for "devil."
Now the board does not have the final say on the issue. That is up to U.S. Board of Geographic names.
However, the agency rejected a similar effort by the same man back in 2005.