Department of Defense, Memorandum for Correspondents Regarding Declassification of the NRO [open pdf - 44KB]
"This is the memo that announced the declassification of the existence of the NRO and provided the sum total of declassified information as of that date. Comparison of the release to some of the preparatory memos, indicates a number of items of information that had been considered for declassification - including information on organization and the identities of directorate chiefs - but that were not declassified at first."
2008 National Security Archive
National Security Archive: http://www.gwu.edu/~nsarchiv/