Regional definitions vary from source to source. The states shown in dark red are usually included, while all or portions of the striped states may or may not be considered part of the Mountain States.
The
Mountain States (also known as the
Mountain West) form one of the nine geographic divisions of the
United States that are officially recognized by the
United States Census Bureau.
The division consists of eight states:
Arizona,
Colorado,
Idaho,
Montana,
Nevada,
New Mexico,
Utah, and
Wyoming. Together with the
Pacific States of
Alaska,
California,
Hawaii,
Oregon and
Washington, the Mountain States constitute the broader
region of the
West, one of the four regions the
United States Census Bureau formally recognizes (the
Northeast,
South and
Midwest being the other three). The word "Mountain" refers to the
Rocky Mountains, which run north-south throughout the division.
Mountain Standard Time is observed in nearly the entire division, except Nevada (all but the stateline city of
West Wendover), the Idaho
panhandle, and most of Arizona. Lands within the
Navajo Nation (Northeast corner of the state) observe daylight saving time due to the Nation traversing state lines.
Arizona is one hour behind Mountain Standard Time from the second Sunday in March until the first Sunday in November, because
daylight saving time is not observed in Arizona.
Phoenix is the largest city in the mountain states followed by
Denver and
Las Vegas.
In their geopolitical book
The Day America Told The Truth,
James Patterson and
Peter Kim place most of the territory found within the Mountain States in a
moral region they label
Marlboro Country, with the division's eastern and southern salients being slotted into their
Granary and
L.A.-Mex regions respectively.
