census.gov-zcta_county-1.1.1 Last Update: 2020-11-09T22:18:53
Maps Cenus zip-code tabulation areas to Counties
This file links Ztca regions -- the Census version of ZIP codes, to counties, by associating a Zcta with the county that contains the Zctas centroid.
There are only about 1/2 the number of Zctas in this file ( 33K ) as there are ZIP codes ( about 77K )