COUNTY · OK
Harper County, Oklahoma
Harper County is a county in Oklahoma with FIPS code 40059 and an estimated population of 3,190 (Census 2023), 75th largest of 77 in the state.
County facts
- Name
- Harper County
- State
- Oklahoma
- Type
- county
- FIPS code
- 40059
- State FIPS
- 40
- Population (2023)
- 3,190
- Change since 2020
- -1.9%
- State rank
- 75 of 77
Population is the Census Bureau’s Vintage 2023 estimate.
Questions
What is the FIPS code for Harper County?
Harper County, Oklahoma has the five-digit FIPS code 40059: 40 for the state and 059 for the county.
What state is Harper County in?
Harper County is in Oklahoma.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.