(FORTUNE Magazine) – Back in the 1950s, storage company Iron Mountain built hideaways for 150 top executives in case of a nuclear blast. These days the company deals in all kinds of data, and it made headlines in May after a stash of backup tapes belonging to Time Warner (FORTUNE's parent) were lost en route to a safe house. Here's a look at corporate America's biggest recordkeeper. -- Julia Boorstin

95% of the companies in the FORTUNE 1,000 use Iron Mountain to store everything from paper records to server back-up tapes to original Hollywood movie reels.

500 million data tapes are in circulation at any given time. Companies constantly update old tapes with the latest snapshot of their files.

883 sites around the world house data tapes and papers, most at a climate-controlled 68 to 72 degrees and less than 45% humidity.

14,500 employees, all of whom have undergone a drug test and background check, work at Iron Mountain.*

2,750 white trucks and vans, retrofitted with two extra locks and an alarm system, transport boxes from company loading docks to storage centers.

12 times a year data tapes are lost. That's a delivery accuracy rate of 99.99976% (just hope you're not among the 0.00024%).

*Not including subcontractors.