fun fact about 413:

>Because of the low population density of western Massachusetts, 413 remained in its original configuration even as the eastern portion of the state went from one area code to four from 1988 to 1997. As a result, 413 is the only original numbering plan area of Massachusetts that still maintains its original boundaries, and is one of the few original area codes (not counting those that cover an entire state) that has never been split or overlaid despite the proliferation of cell phones and pagers, particularly in and around Springfield. The projected exhaust date for 413 is 2041

from Wikipedia.