Area Code 605-278 located in RALPH, HARDING, SD, more detail is as below. Place NPA (Numbering Plan Area) : 605 NXX (Local Number Prefix) : 278 City : RALPH County : HARDING State : SD (South Dakota) NXX Use Type : Landline NXX Intro Version : 1996-01-10 FIPS (Federal Information Processing Standards) : 46063 LATA (Local Access Transport Area) : 638 Rate Center : SOSCRANTON ZIP Code Count : 1 ZIP Code Frequency : 3 ZIP Code : 57650 Other Information NPANXX : 605278 County Population : 0 Switch CLLI (Common Language Location Identifier) : SCTNNDXA27G Time Zone : Mountain (GMT -07:00) Observes Daylight Saving Time : Yes Company : CONSOLIDATED TELCOM OCN (Operating Company Number) : 1607 Coverage Area Name : RALPH Latitude : 45.9147 Longitude : -103.1690 ‹ previous : 605-278 next › : 605-278 Telephone Number List 605-278-0000 ~ 605-278-9999