Area Codes
| 810 | Michigan (Port Huron, Flint, Lapeer, and Michigan "Thumb", (originally split from 313 and included areas that later became 248 and 586) |
| 810 | Michigan (Port Huron, Flint, Lapeer, and Michigan "Thumb", (originally split from 313 and included areas that later became 248 and 586) |