NPA-NXX - 307-640

This is the 307-640 subcode (NPA-NXX) prefix page. Follow a prefix to find the number you are looking for. We divide our pages up to make them more user friendly to navigate!

1. Area Codes
2. 307
3. 307-640

The 307-640 subcode mainly covers Cheyenne in Laramie county. But other numbers maybe included as well.

We have a database of information derived from the public phone records of Wyoming state. Many of the numbers in this subcode are Cellular (Dedicated) registered to At&t Mobility. We hear they employ a large number of people in the Wyoming office.
Recently there have been an increase in reported calls, we've had over 91738 comments across our systems for the 307-640 subcode.