Area code and exchange code is assigned to every constituent of city in the United States. The area and exchange codes of the telephone can be used to find information about a region. Area code 450 and exchange code 278 is assigned to Saint Hyacinthe. The latitude and longitude corresponding to 45.62 and -72.95 can be used to find an area on the map. Telus Mobilityoperates most of the land lines in United States.