Area Code 307-257 located in GILLETTE, CAMPBELL, WY, more detail is as below. Place NPA (Numbering Plan Area) : 307 NXX (Local Number Prefix) : 257 City : GILLETTE County : CAMPBELL State : WY (Wyoming) NXX Use Type : Landline NXX Intro Version : 2004-12-13 FIPS (Federal Information Processing Standards) : 56005 LATA (Local Access Transport Area) : 654 Rate Center : GILLETTE ZIP Code Count : 0 ZIP Code Frequency : Most frequently occurring ZIP Code, although percentage is unknown. ZIP Code : 82718 Other Information NPANXX : 307257 County Population : 0 Switch CLLI (Common Language Location Identifier) : CSPRWYMAUMD MSA CBSA (Core Based Statistical Area) : Gillette, WY MSA CBSA Code (Core Based Statistical Area) : 23940 Time Zone : Mountain (GMT -07:00) Observes Daylight Saving Time : Yes Company : LEVEL 3 COMMUNICATIONS, LLC - WY OCN (Operating Company Number) : 9416 Coverage Area Name : GILLETTE Latitude : 44.2926 Longitude : -105.4886 ‹ previous : 307-256 next › : 307-258 Telephone Number List 307-257-0000 ~ 307-257-9999