670 Area Code: Saipan, Northern Mariana Islands

The 670 area code serves the Commonwealth of the Northern Mariana Islands, a US territory in the western Pacific roughly 1,500 miles east of the Philippines. Saipan, the largest island and the territory's capital, anchors the directory's records here. The Northern Marianas comprise a chain of fifteen islands stretching north from Guam, with Saipan, Tinian, and Rota as the three inhabited islands; the islands have a long-running history shaped by Spanish, German, Japanese, and American administration before the establishment of the current commonwealth status. The 670 designation joins the territory to the same dialing framework used across the United States and several other Pacific and Caribbean territories.

Because 670 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, they reflect the same kinds of public-record dynamics seen elsewhere — numbers porting between carriers, addresses tied to multiple jurisdictions, and prior registrations surfacing alongside current ones. The directory currently documents 3 distinct prefixes within 670 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 the Northern Mariana Islands in the same form as for the fifty states, and the standard four-metric profile is not currently available for Saipan. The territory's overall population has historically counted in the high tens of thousands, with most residents concentrated on Saipan.