Area Codes
| 641 | Iowa (Mason City, Oskaloosa, Creston, Pella, Ottumwa, Britt, Clear Lake, Fairfield and central Iowa) | More information at: Area Code 641 Phone Number Blocks
| 641 | Iowa (Mason City, Oskaloosa, Creston, Pella, Ottumwa, Britt, Clear Lake, Fairfield and central Iowa) | More information at: Area Code 641 Phone Number Blocks