Area Code 303-312 located in LITTLETON, ARAPAHOE, CO, more detail is as below. Place NPA (Numbering Plan Area) : 303 NXX (Local Number Prefix) : 312 City : LITTLETON County : ARAPAHOE State : CO (Colorado) NXX Use Type : Landline NXX Intro Version : 1995-02-11 FIPS (Federal Information Processing Standards) : 08005 LATA (Local Access Transport Area) : 656 Rate Center : DENVER ZIP Code Count : 1 ZIP Code Frequency : 7 ZIP Code : 80122 Other Information NPANXX : 303312 County Population : 0 Switch CLLI (Common Language Location Identifier) : DNVRCOCPDS0 MSA CBSA (Core Based Statistical Area) : Denver-Aurora, CO MSA CBSA Code (Core Based Statistical Area) : 19740 Time Zone : Mountain (GMT -07:00) Observes Daylight Saving Time : Yes Company : QWEST CORPORATION OCN (Operating Company Number) : 9636 Coverage Area Name : DENVER Latitude : 39.7542 Longitude : -104.9856 ‹ previous : 303-312 next › : 303-312 Telephone Number List 303-312-0000 ~ 303-312-9999