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IRON MOUNTAIN INCORPORATED

Vote In Person

745 ATLANTIC AVENUE

BOSTON, MA 02111

Many shareholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the Meeting you will need to request a ballot to vote these shares.

Vote By Internet

To vote now by Internet, go to WWW.PROXYVOTE.COM.  Use the Internet to transmit your voting instructions and for electronic delivery of information up until 11:59 P.M. Eastern Time the day before the cut-off date or meeting date. Have your notice in hand when you access the web site and follow the instructions.

The Annual Meeting for holders as of April 10, 2008

is to be held on June 5, 2008 at 10:00 A.M. EDT to consider

the voting items set forth on the next page

From Points West:

at:

Offices of Sullivan & Worcester

1 Post Office Square

Boston, MA 02109

Take the Massachusetts Turnpike (1-90) into Boston. Take exit 24B to 1-93 North, and then take exit 23, Government Center. Stay left off the exit (following signs for Govt. Center/Faneuil Hall). Take your first left onto North Street, follow it to the end and turn left onto Congress Street. At the third light turn left onto Milk Street. Take your second right onto Oliver Street. Enter the garage to the right through the private way between the Langham hotel and the office building.

Directions to the meeting:

From Points North:

From Logan Airport:

Take 1-93 South to exit 24, toward Callahan Tunnel/Logan Airport. Turn right onto North Street, then left onto Congress Street. At the third light turn left at Milk Street. Take your second right onto Oliver Street. Enter the One Post Office Square parking garage to the right through private way between the Langham hotel and the office building.

Follow signs for Boston through the Sumner Tunnel. After exiting the tunnel follow the signs for 1-93 South to exit 24, toward Callahan Tunnel/Logan Airport. Turn right onto North Street, then left onto Congress Street. At the third light turn left at Milk Street Take your second right onto Oliver Street. Enter the parking garage to the right through private way between the Langham hotel and the office building.

From the Prudential Center, Copley Square

From Points South:

or Boylston Street (Backbay):

Take 1-93 North to exit 23, Government Center. Stay left off the exit (following signs for Govt. Center/Faneuil Hall). Take your first left onto North Street, follow it to the end and turn left onto Congress Street. At the third light turn left onto Milk Street. Take your second right onto Oliver Street. Enter the garage to the right through the private way between the Langham hotel and the office building.

Take Boylston Street toward the Boston Common. Turn left onto Charles Street. Turn right onto Beacon Street. Beacon Street crosses Tremont Street and becomes School Street. At the end of School Street turn left onto Washington Street and immediately right onto Water Street. Follow Water Street three blocks to a large statue at Liberty Square and turn right onto Kilby Street. Cross Milk Street and enter the garage to the right through the private way between the Langham hotel and the office building.

1.

The election of nine (9) directors to the Iron

Mountain Incorporated board of directors

for a one-year term or until their successors

are elected and qualified;

Nominees:

01)

Clarke H. Bailey

06)

Arthur D. Little

02)

Constantin R. Boden

07)

C. Richard Reese

03)

Robert T. Brennan

08)

Vincent J. Ryan

04)

Kent P. Dauten

09)

Laurie A. Tucker

05)

Michael Lamach

2.

The approval of an amendment to the Iron Mountain Incorporated 2002 Stock Incentive Plan to increase the number of shares of Common Stock authorized for issuance thereunder by 7,500,000 from 12,528,815 to 20,028,815 and extend the termination date thereunder from March 31, 2012 to March 31, 2018.

3.

The approval of an amendment to the Iron Mountain Incorporated 2006 Senior Executive Incentive Program to modify the definition of participant, increase the maximum compensation payable thereunder and modify and re-approve the payment criteria thereunder.

4.

The approval of an amendment to the Iron Mountain Incorporated 2003 Senior Executive Incentive Program to modify and re-approve the payment criteria thereunder.

5.

The ratification of the selection by the Audit Committee of Deloitte & Touche LLP as Iron Mountain Incorporated’s independent registered public accounting firm for the year ending December 31, 2008; and

6.

In their discretion, the Proxies are authorized to vote upon such other business as may properly come before the meeting or any adjournment or postponement thereof.

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