AT&T "Project Office"


This station is an active AT&T network facility. AT&T Corporate Security has requested that the names and exact locations of such facilities not be published. Accordingly, it is identified on this web page only by its Common Language Location Identifier (CLLI) code, HGTWMDQ0010.


Located atop a mountain in Maryland just south of Pennsylvania, HGTWMDQ0010 is the northernmost of five "Project Office" stations built by AT&Tduring the 1960s in the mid-Atlantic region. The station is hardened against nuclear blasts, and features an earth-covered underground building with a "drive-through" entrance-decontamination area, a high-powered troposcatter radio communications system with large concrete-backed reflectors, a helipad, blast-resistant terrestrial microwave "dish" antennas, and physical-security measures beyond those used at conventional AT&T facilities.

Detailed information about HGTWMDQ0010's function has never been revealed. The facility housed a switching system for the Department of Defense's AUTOVON telephone network, but that was probably not the station's primary mission. It's likely that HGTWMDQ0010 supported a highly-classified Continuity of Goverment program and may have served as an emergency relocation site for senior executive-branch officials and/or military leadership.

HGTWMDQ0010 is still an active, secure AT&T facility, and unofficial visitors are not permitted.

Aerial images

Photographed December 18, 2005 by Mike Jacoby
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Ground images

Photographed March 25, 2001
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Updated on January 19, 2006 at 19:37 by Albert LaFrance