This map shows the distribution of wire centers in the USA and Canada. A given NPA/NXX pair will map to exactly one of these points. Each of these points may serve from 1-30 exchanges. The map is a gnomonic projection: straight lines are great circle paths, angles are true. [Click the image for a larger map.]
A 3.7 MB April 1999 ascii database of these exchanges and wire centers is available on line. The format is:
npa nxx lat lng u st city 201 200 40.71 074.07 L NJ Jersey City 201 202 40.85 074.04 W NJ Little Ferry 201 203 40.79 074.48 W NJ Morristown (L and W mean land or wireless use)
A 3.5 MB January 1998 database is kept here also. At that time there were 95543 NPA/NXX's served by 24269 wire centers.
For related information, see:
These databases and maps were prepared by the author, P. Dykstra, June 1999.