The United States acquired the area of Oregon by a treaty with Great Britain in 1846. Oregon Territory was organized from the acquired area on August 14, 1848, and included all of present-day Oregon, Idaho, and Washington and part of western Montana and Wyoming. The territory was reduced in 1853 when Washington Territory was organized. In 1859, additional territory was transferred to Washington Territory, leaving Oregon with generally the same boundary as the present state.

Census data for Oregon are available beginning with the 1850 census. The 1850 population is for the area in present-day Oregon; it does not include the entire territory as legally established. The population of Oregon Territory as legally constituted in 1850 was 13,294.

Data for the legally established state of Oregon are available beginning with the 1860 census.

AMERICAN INDIAN AREAS

Oregon has 11 American Indian area reservations, 6 with off-reservation trust land.

METROPOLITAN AND MICROPOLITAN STATISTICAL AREAS AND RELATED STATISTICAL AREAS

Oregon has 6 metropolitan statistical areas, 13 micropolitan statistical areas, and 2 combined statistical areas.

COUNTIES

Oregon has 36 counties.  All counties are functioning governmental units, each governed by a board of county commissioners. 

COUNTY SUBDIVISIONS

There are 212 county subdivisions in Oregon. 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 Oregon for the 1960 census.  Prior to 1960, the minor civil divisions used in the census were election precincts.

PLACES

Oregon has 377 places; 242 incorporated places and 135 census designated places (CDPs).  The incorporated places consist of 233 cities and 9 towns.  There is one inactive city, Greenhorn.  The minimum population for incorporation is 150. 

CENSUS TRACTS/BLOCK GROUPS/BLOCKS

Oregon has 834 census tracts, 2,634 block groups, and 196,621 blocks.

CONGRESSIONAL DISTRICTS

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

SCHOOL DISTRICTS

Oregon has 9 elementary school districts, 1 secondary school district, and 188 unified school districts.

STATE LEGISLATIVE DISTRICTS

There are 30 state senate districts and 60 state house districts in Oregon.

URBAN AREAS

Oregon has 71 urban areas; 10 urbanized areas and 61 urban clusters.

ZIP CODE TABULATION AREAS

There are 419 ZIP Code tabulation areas (ZCTAs) in Oregon.

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