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Boulder, Montana

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Census Data for Boulder ...

Population ...

The most recent Census Estimate<1> was for 2019 and it gave Boulder a population of 1,276 people.

The last Decennial Census<2> was in 2010, which gave Boulder a population of 1,183 people.

The town of Boulder is located in Jefferson County. The 2010 Census gave Jefferson County; a population of 11,406 people. This means that Boulder had 10.37% of the county's total population, making it Jefferson's most populous community.

At the same time, Montana had a population of 989,415 people, meaning that Boulder had 0.12% of the total population of Montana - making it the state's 50th most populous community.

Area ...

The 2010 Census shows that the sampling area for Boulder has a total area of 1.13 square miles [2.9 km²].

Jefferson County has a land area of 1,656 square miles [4,289.7 km²]. At 1.13 square miles [2.9 km²], Boulder has 0.07% of the county's total land area.

  • Continue Reading ...
    • When the Census Bureau conducts a census for a town like Boulder, they draw a boundary around the area in which they are going to conduct their count - this defines the sampling area (usually a polygon). The shape of the sampling area can be quite complex and it's important to keep in mind that the boundaries of the sampling area may or may not match the recognized boundaries of the town.
    • Things like population, area and housing for Boulder reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Boulder might be different, it's best to check with the U.S. Census Bureau to resolve any difference between the two.
    • Not only does the sampling area define boundaries, it also has a GPS location (latitude & longitude) that indicates a point within the sampling area (usually the center of the polygon, known as the centroid). At the time of the 2010 Census, the sampling area was located at:
    • Lat:   46° 14' 8"   (or 46.24°)
    • Lon:   -112° 7' 13"   (or -112.12°)
    • More information on this topic and the changes between the 2000 Census and the 2010 Census can be found in the section for our Census-to-Census Observations ... (see below).

Housing Units ...

At the time of the 2010 Census, Boulder had 565 Housing Units<3> and with its population of 1,183 people, this averages 2.09 people per Housing Unit.

  • Continue Reading ...
    • The 2010 Census shows Boulder had a land area of 1.13 square miles [2.9 km²]. This translates to 498.2 Housing Units per square mile [192.4 housing units/km²].
    • From the Census of 2000: Boulder had 568 Housing Units, a population of 1,300 people and a land area of 1.14 square miles [2.9 km²]. This gives a density of 2.29 people per Housing Unit and 499.3 Housing Units per square mile [192.8 housing units/km²].
    • Note: Repeating the caution above (under Population Density), be aware that when comparing Housing Units between the 2010 and the 2000 Census, there were changes in the sampling area for Boulder and you need to be careful when comparing between the censuses. More information about the nature of these the changes can be found in the section called Census-to-Census Observations ... (see below).

Jefferson County ...

The community of Boulder is located in Jefferson County<4> and is the County Seat for Jefferson County.

The county had a population of 11,406 people at the 2010 Census. With it's population of 1,183 people, Boulder represented 10.37% of the county's total.

In addition, where the town of Boulder has a population density of 1,043 people per square mile [402.8 people/km²], Jefferson County averages 6.89 people per square mile [2.66 people/km²].

For more information, please visit our Census Page for Jefferson County.

Census-to-Census Observations ...

Introduction ...

When the Census Bureau takes a census count (or enumeration) for Boulder, they start by specifying the boundaries of the area to be counted. This area (or sampling area) is a polygon and its shape can be quite complex - it may or may not match the geographical boundaries of Boulder. It's important to note that from one Census to the next, the shape and location of the polygon can change.

  • Continue Reading ...
    • Although we don't have specific information about the shape of the polygon for Boulder or how it changed has over time, there is some information that can give us some hints. For example, since the shape of the sampling area is directly related to the shape of the polygon, any change to area probably indicates a new shape for the polygon.
    • If you need precision or details about the methodology of the Census, you should visit the U.S. Census Bureau for a definitive answer.

Location ...

While generally coinciding with the GPS location (latitude/longitude) of Boulder, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Boulder.

  • Continue Reading ...
    • For the 2010 Census, the location was given as:
    • Lat:   46.235684°   (or 46°14'8" N)
    • Lon:   -112.120529°   (or -112°7'13" W)
    • For the 2000 Census, the location given was:
    • Lat:   46.236300°   (or 46°14'10" N)
    • Lon:   -112.121823°   (or -112°7'18" W)
    • The difference indicates that the U.S. Census Bureau moved the location of the polygon for the 2010 Census 396.1 feet to the southeast<5> of the location that was used in the 2000 Census.
    • The U.S. Geological Survey (USGS) and the U.S. Board on Geographic Names (BGN) have assigned a unique GNIS identifier (#2411712) to Boulder. This identifier also marks a GPS point on the map, and that point lies within the boundaries of Boulder. The GNIS point has been mapped to the latitude/longitude:
    • Lat:   46.235842°   (or 46°14'9" N)
    • Lon:   -112.120630°   (or -112°7'14" W)
    • The GPS location given for the 2010 Census lies 63 feet to the southeast<6> of the point given by the GNIS for Boulder. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Boulder.

Miscellaneous Information for Boulder ...

The Federal government has assigned various identifying codes to each community, county and state. At one time or another, the US Census Bureau has used one (or more) of the following identifiers when referring to either Jefferson County or the town of Boulder:

  • The GNIS Codes ...
    • The current system of identification is called the Geographic Names Information System (GNIS). The following GNIS codes relate to Boulder:
    • GNIS ID for Boulder: 2411712
    • GNIS ID for Jefferson County: 1720045
    • GNIS ID for State of Montana: 767982
  • The FIPS Codes ...
  • Misc. Census Codes ...
    • Boulder is located in Census Region #4 (the West Region) and Division #8 (the Mountain Division).
  • The US Postal Service ZIP Code ...
    • While some people have used a ZIP code to identify a community, the purpose of the ZIP code was to make mail delivery more efficient by grouping addresses together. Although the ZIP Code doesn't specifically identify a town like Boulder, it does identify addresses that are in (or near) Boulder. It's important to remember that the boundaries of a ZIP Code can be changed, re-assigned or overlapped with other ZIP Codes.
    • The ZIP code for Boulder:59632<7>
  • Census ZCTA Codes ...
    • The US Census Bureau created statistical entities that they call ZIP Code Tabulation Areas (ZCTAs) and these ZCTAs are frequently confused with the ZIP codes that come from the US Postal Service (USPS).
    • ZCTAs were first created for the 2000 Census and at that time, they were based upon the USPS ZIP codes. While largely covering the same areas, the boundaries of a ZCTA do not necessarily match the boundaries of a postal ZIP code with the same number. For example, while a postal ZIP code can cross a county or state line, a Census ZCTA can not. They should be treated as separate entities with no correlation between them.

For more information about the various Federal identification codes, please visit our Misc Page for Boulder.

Other Roadside Stops ...

Index of Cities, Towns and Villages for Montana

About Jefferson County

About Montana

Off-the-Road Links ...

Unfortunately, we don't know of a website for Boulder. If you can help, please contact us through our Feedback Page.

The official website for Jefferson County:

The official website for State of Montana:

The official website of the U.S. Census Bureau

The official website of the U.S. Board on Geographic Names (BGN)

The official website of the U.S. Geological Survey (USGS)

Footnotes ...

<1>Every year, the US Census Bureau creates a population estimate for the preceeding year. Keep in mind that this value is an estimate and not an actual count. The most recent Census estimate is for the year 2019.
<2>Every 10 years (eg- 1990, 2000, 2010), the US Census Bureau conducts a Constitutionally-mandated count (or enumeration) of people living within the United States. This count is called a Decennial Census. The last Decennial Census was the 2010 Census, with the next one planned for 2020.
<3>A Housing Unit is a broad term for those places where people live (whether occupied or temporarily vacant), such as a house, an apartment, a mobile home, or an area that is considered as a separate living quarter. Separate living quarters (consisting of one or more rooms) are considered to be those places where people live, sleep and eat separately from others and that have access to the outside (either directly or by a shared hallway).
<4>If you're interested in how the shape of Montana's counties, including Jefferson, have changed over time, we recommend the Atlas of Historical County Boundaries.
<5>The calculated bearing (or angle) to the 2010 Census location is 235 degrees and a distance of 396.1 feet.
<6>The calculated bearing (or angle) to the GNIS point is 203 degrees and a distance of 63 feet.
<7>When looking for a ZIP Code, whether Boulder or elsewhere, it's always best to check the website of the United States Postal Service (USPS).






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This page was last modified: 27 Apr 2022