The United States acquired the area of Montana from France as part of the Louisiana Purchase in 1803 and by a treaty with Great Britain in 1846. Montana Territory was organized from the northeastern part of Idaho Territory on May 26, 1864, with generally the same boundary as the present state.

Census data for Montana are available beginning with the 1870 census. The 1860 census population in present-day Montana was included in unorganized Dakota, although legally the area was within Nebraska and Washington territories. The portion of Yellowstone National Park in Montana was probably enumerated as part of Wyoming from 1880 to 1910.

Data for the legally established state of Montana are available beginning with the 1890 census.

American Indian Areas

Montana has eight federally recognized American Indian areas.  There are seven reservations, six with off-reservation trust lands. There is also one off-reservation trust land associated with an American Indian reservation in a neighboring state.

Metropolitan And Micropolitan Statistical Areas And Related Statistical Areas

Montana has three metropolitan statistical areas and five micropolitan statistical areas.

Counties

There are 56 counties in Montana.  Two counties are not considered to be functioning governmental units because each has consolidated its functions with an incorporated place.  Deer Lodge County and Anaconda-Deer Lodge County (place) are governmentally consolidated.  Silver Bow County and Butte-Silver Bow (place) are governmentally consolidated.  The remaining 54 counties are each governed by a county board of commissioners.

Yellowstone National Park was deleted as a county equivalent when its area legally became part of Gallatin and Park Counties on November 7, 1997.

County Subdivisions

There are 194 county subdivisions in Montana. They are all census county divisions (CCDs), which are delineated for statistical purposes, have no legal function, and are not governmental units.  CCDs were first established in Montana for the 1960 census.  Prior to 1960, the minor civil divisions used in the census included election precincts, election districts, townships, land survey townships, American Indian reservations, and school districts.

Places

Montana has 364 places; 129 incorporated places and 235 census designated places (CDPs).  The incorporated places consist of 52 cities, 75 towns, 1 city with no description - Anconda-Deer Lodge County - and 1 balance of county for the area of the Butte-Silver Bow consolidated city outside of the incorporated place of Walkerville city.  Anaconda-Deer Lodge County is coextensive with Deer Lodge County.

Census Tracts/Block Groups/Blocks

Montana has 271 census tracts, 842 block groups, and 132,288 blocks.

Congressional Districts

For the 111^th Congress (January 2009-January 2011), Montana had one congressional district.  For the 113^th Congress (January 2013-January 2015), Montana continues to have one congressional district as a result of reapportionment based on the 2010 Census.

School Districts

Montana has 267 elementary school districts, 108 secondary school districts, and 52 unified school districts.

State Legislative Districts

There are 50 state senate districts and 100 state house districts in Montana.

Urban Areas

Montana has 33 urban areas; 3 urbanized areas and 30 urban clusters.

Zip Code Tabulation Areas

Montana has 363 ZIP Code tabulation areas (ZCTAs).

¹  Source:  U.S. Department of Commerce, Bureau of the Census, Fourteenth Census of the United States, 1923
²  Source:  U.S. Census Bureau, recomputation for historical county level data which relied upon aggregate county level population data with an estimated county centroid resulting in a possible error of up to one mile.
³  Source:  U.S. Department of Commerce, Bureau of the Census, Centers of Population for States and Counties, 1974
⁴  Source:  U.S. Census Bureau, Geography Division, recomputation from archived national block group/enumeration area data resulting in a possible error of up to 1,000 feet.
⁵  Source:  U.S. Census Bureau, Geography Division, recomputation from archived national block group data resulting in a possible error of up to 1,000 feet.
⁶  Source:  U.S. Census Bureau, computation from national block-level data