Area Code 307-377 located in CASPER, NATRONA, WY, more detail is as below. Place NPA (Numbering Plan Area) : 307 NXX (Local Number Prefix) : 377 City : CASPER County : NATRONA State : WY (Wyoming) NXX Use Type : Wireless NXX Intro Version : 1998-11-20 FIPS (Federal Information Processing Standards) : 56025 LATA (Local Access Transport Area) : 654 Rate Center : CASPER ZIP Code Count : 2 ZIP Code Frequency : 100 ZIP Code : 82601 Other Information NPANXX : 307377 County Population : 0 Switch CLLI (Common Language Location Identifier) : MNVWWYXCCM2 MSA CBSA (Core Based Statistical Area) : Casper, WY MSA CBSA Code (Core Based Statistical Area) : 16220 Time Zone : Mountain (GMT -07:00) Observes Daylight Saving Time : Yes Company : UNION TELEPHONE COMPANY OCN (Operating Company Number) : 013B Coverage Area Name : CASPER Latitude : 42.8413 Longitude : -106.3263 ‹ previous : 307-375 next › : 307-378 Telephone Number List 307-377-0000 ~ 307-377-9999