Mountain Time Zone Area Codes: The Interior West
The Mountain Time Zone covers the Rocky Mountain states, the high desert, and the Canadian prairies. Here's a guide to the area codes of this vast interior region.
America's Interior
The Mountain Time Zone (UTC-7 in winter, UTC-6 in summer) covers the Rocky Mountain states and stretches north into the Canadian prairies of Alberta and Saskatchewan. It's the least densely populated time zone in the continental US, characterized by wide-open spaces, mountain ranges, high desert plateaus, and a relatively small number of large cities.
Colorado: Two Codes
Colorado is served by 303 (Denver metro, the original code) and 719 (southern and eastern Colorado). An overlay, 720, was added to relieve pressure in the Denver area. Colorado's rapid population growth in recent decades has increased demand significantly.
Arizona: No Daylight Saving Time, Multiple Codes
Arizona (except the Navajo Nation) does not observe Daylight Saving Time, which creates an interesting situation where Arizona is on Mountain Time in winter but effectively Pacific Time in summer. Arizona uses 602 (Phoenix metro), 480 (East Valley), 623 (West Valley), and 520 (Tucson and southern Arizona).
Utah, Nevada, Idaho, Montana, Wyoming
These states each have one or two area codes reflecting their modest populations. Utah uses 801 (Salt Lake City) and 435 (rest of state). Nevada uses 702 (Las Vegas) and 775 (rest of Nevada). Idaho uses 208 for the entire state. Montana (406) and Wyoming (307) each have one code for their entire state.
Canada's Mountain Zone
Alberta uses 403 (Calgary and southern Alberta) and 780 (Edmonton and northern Alberta). Saskatchewan uses 306 for the whole province. See all Mountain Time codes at Mountain Time Zone.
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