Underground storage facilities

I'm trying to compile information on (underground) storage facilities
that would be suitable repositories for either preservation master
negatives or printing masters.  Neither MOODY'S nor LIBRARY LITERATURE
have been of any help in identifying vendors. I have thus far identified
four such companies:  Iron Mountain, National Underground Storage,
Underground Vaults & Storage and Western States Underground Vaults.

Can anyone provide the names and addresses of other suitable storage
facilities, whether underground or not?  Any comments you can offer
regarding the kinds of service provided by a vendor with which you've
done business would be appreciated.

Thank you.

Regina Sinclair
Mellon Intern in Preservation Administration

                                  ***
                  Conservation DistList Instance 4:39
                 Distributed: Sunday, January 20, 1991
                        Message Id: cdl-4-39-001
                                  ***