Area Code 301-831 located in ADAMSTOWN, FREDERICK, MD, more detail is as below. Place NPA (Numbering Plan Area) : 301 NXX (Local Number Prefix) : 831 City : ADAMSTOWN County : FREDERICK State : MD (Maryland) NXX Use Type : Landline NXX Intro Version : 1994-02-04 FIPS (Federal Information Processing Standards) : 24021 LATA (Local Access Transport Area) : 240 Rate Center : DAMASCS240 ZIP Code Count : 205 ZIP Code Frequency : 5 ZIP Code : 21710 Other Information NPANXX : 301831 County Population : 0 Switch CLLI (Common Language Location Identifier) : BCTWMDBTRS0 MSA CBSA (Core Based Statistical Area) : Washington-Arlington-Alexandria, DC-VA-MD-WV MSA CBSA Code (Core Based Statistical Area) : 47900 Time Zone : Eastern (GMT -05:00) Observes Daylight Saving Time : Yes Company : VERIZON MARYLAND, INC. OCN (Operating Company Number) : 9212 Coverage Area Name : ADAMSTOWN Latitude : 39.3300 Longitude : -77.4304 ‹ previous : 301-831 next › : 301-831 Telephone Number List 301-831-0000 ~ 301-831-9999