X0303 4 2011-06-29 0 0001020569 IRON MOUNTAIN INC IRM 0001244482 ANTENUCCI TED R C/O IRON MOUNTAIN INCORPORATED 745 ATLANTIC AVENUE BOSTON MA 02111 1 0 0 0 Common Stock, par value, $.01 per share 2011-06-29 4 A 0 2820 0 A 2820 D Consists of shares issuable upon the settlement of restricted stock units granted on June 29, 2011. The restricted stock units vest on the one year anniversary of the grant date (or, if earlier, the annual meeting of stockholders that is closest to the one year anniversary). /s/ Sarah Cammarata, under Power of Attorney dated June 21, 2011, from Ted Antenucci 2011-07-01