County · code 19041
Clay CountyIowa
Clay County is a county in Iowa, with its seat at Spencer, formed in 1851.
- Founded1851
- County seatSpencer
- Named forHenry Clay
- Land area567 sq mi + 5.4 sq mi water
- Population16,384 2020 Census
- Parcels mapped18,706 checked 16 October 2026
Where it is
Clay on the map of Iowa
Iowa has 99 counties and county equivalents, each with its own records office. Shapes with a page are links.
History
Formed in 1851 from Polk County
An old deed may name a county that no longer exists, or a boundary that has since moved.
Clay was created from Polk County in 1851 but was not fully organized at that time. In 1853, Clay was attached to Woodbury County for revenue, election, and judicial purposes, and later fully organized and detached in 1858. The county was named after Henry Clay.
- 1851Clay County created Clay created from Non-County Area 9 attached to Polk; Clay not fully organized, not attached. · Iowa Acts 1850-1851, ch. 9, sec. 39/p. 36
- 1853Changed Clay attached to Woodbury "for revenue, election, and judicial purposes". · Iowa Acts 1852-1853, ch. 8, sec. 14/p. 24
- 1858Changed Clay fully organized, detached from Woodbury. · Swisher, "Organization of Counties," 574
- 1864Changed Buena Vista, Cherokee, and O'Brien attached to Clay "for judicial purposes." · Iowa Acts 1864, ch. 47, secs. 2, 9/pp. 47-49
- 1868
- 1870Changed Buena Vista fully organized, detached from Clay when judicial attachments of 30 March 1864 were repealed. · Iowa Acts 1870, ch. 2, secs. 3-4/pp. 3-4
Land and parcels
What the maps cover in Clay
Who publishes each layer, how good it is, and when we last checked.
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Parcels Good enough
Lot lines and tax-map numbers for 18,706 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 4 November 2025 · checked 16 October 2026 -
Address points Missing
No public address points layer found for Clay County yet.
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Buildings Reference
Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026
- Official
- from the office that keeps the record
- Good enough
- a reliable statewide or national copy
- Fallback
- a guide only; check the official record
- Missing
- nothing public found yet
People and land
Clay by the Census
Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.
Rules and offices
Who to ask before you build, dig or sell
Official county pages only. We link to them; we do not copy them, because they change.
Inside a city or town, permits usually come from that city rather than the county.
Zoning and code
County government
- County government
The official website of Clay County.
See your own lot on these maps
Open Clay County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.
Questions
Common questions about Clay County
- When was Clay County founded?
- Clay County was founded in 1851, formed from Polk County, and named after Henry Clay.
- What is the county seat of Clay County?
- The county seat of Clay County is Spencer.
- Is there an online parcel map for Clay County?
- Yes. A public source publishes a parcel map of 18,706 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Clay County's boundary or name changed?
- Clay County was created in 1851 from Polk County. Since then the Atlas of Historical County Boundaries records 5 later changes, chiefly involving Buena Vista County, Cherokee County and O'Brien County.
- Is my lot in a flood zone?
- We do not have flood maps for Clay County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby