ZIP codes in Yankton County
10 ZIPs touch Yankton County, South Dakota. The blue dashed line is the county border; orange ZIPs reach into it.
10
ZIP codes
7
cross the county line
27,120
people in these ZIPs
66
counties in SD
Most people
Yankton County ZIP list
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Questions people actually ask
How many ZIP codes are in Yankton County, South Dakota?
10 ZIP codes reach into Yankton County. 7 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Yankton County has the most people?
57078 (Yankton) has about 20,383 residents, the most of any ZIP touching Yankton County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Yankton County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Yankton County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
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Updated 2026-11-10 · Where the data comes from