what's montana's area code
Area code 406. The map to the right is clickable; click on an area code to go to the page for that code. Coordinates: 47Â°00â²01â³N 109Â°45â²04â³W / 47.00028Â°N 109.75111Â°W / 47.00028; -109.75111 (State of Montana) Area code 406 is the telephone area code covering the entire state of Montana. It has been Montana's area code since area codes were created in 1947.