1970 County Group Definitions
Summary
1970 county groups are identified by the CNTYGP97 variable in the IPUMS USA 1970 Metro samples, which were originally called the "county group samples."
There are a few major differences between 1970 county groups and the most similar units identified in later samples (county groups in 1980 and PUMAs in 1990 and later samples):
- For PUMAs and 1980 county groups, the minimum population is 100,000. For 1970 county groups, it is 250,000.
- PUMAs and 1980 county groups nest within states, but 1970 county groups do not. (Many 1970 county groups straddle state boundaries.)
- Many PUMAs and 1980 county groups encompass only parts of counties, but every 1970 county group is comprised of one or more whole counties, with one exception: in Hawaii, 1970 county group 14901 corresponds to the city of Honolulu, and county group 14902 covers the remainder of the state, including Honolulu County outside of the city of Honolulu.
Composition File
This Excel file provides a detailed listing of the counties (or county parts) comprising each 1970 county group:
Maps
Maps of 1970 county groups are provided through the links below. On the maps, the large numbers identify the first three digits of the county group code, and the smaller numbers identify the last two digits. (Leading zeros are not printed.)
- Map Legend
- 1: Northeast & Mid-Atlantic
- 1a: Mid-Atlantic Inset
- 2: Eastern Midwest
- 3: Central & Northern Plains
- 4: Central & Northern Mountain West
- 5: Central & Northern Pacific
- 6: California, Nevada, Utah, Arizona
- 7: Southern Rockies & Plains
- 8: Western Southeast
- 9: Eastern Southeast
- 10: Alaska & Hawaii
- 11: Puerto Rico
Boundary File
- 1970 county groups (shapefile within a .ZIP file)
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