671 Area Code: Dededo, Guam

The 671 area code serves Guam, a US territory in the western Pacific roughly 1,500 miles east of the Philippines. Dededo, the most populous village on the island, anchors the directory's records here. Guam's geography is unusual relative to the fifty states: the island is around 30 miles long, with a flat coral plateau in the north (where Andersen Air Force Base sits) giving way to volcanic hills and a southern coastline that runs along a chain of small bays and inlets. The 671 designation joins Guam to the same dialing framework used across the United States and several other Pacific and Caribbean territories.

Because 671 covers a single territory and has limited overlap with the public-record sources that drive much of our cross-city linkage in the fifty states, the directory does not currently surface a recurring set of secondary cities for this code. Where other-place names do appear in records, they reflect the same kinds of public-record dynamics seen elsewhere — numbers porting between carriers, addresses tied to multiple jurisdictions, and prior registrations that surface alongside current ones. The directory currently documents 26 distinct prefixes within 671 in detail, a working subset of the active prefix population.

Demographic figures we use to compare cities to US medians are not represented in our data for Guam in the same form as for the fifty states, and the standard four-metric profile is not currently available for Dededo. The territory's overall population, though, has historically sat in the high one-hundred thousands, with most residents concentrated in the central and northern parts of the island.