County · code 19133
Monona CountyIowa
Monona County is a county in Iowa, with its seat in Onawa. It was created on January 15, 1851.
- Founded1851
- County seatOnawa
- Land area694 sq mi + 4.9 sq mi water
- Population8,751 2020 Census
- Parcels mapped20,388 checked 15 October 2026
Where it is
Monona 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.
Monona County was created from Polk County in 1851 but was not fully organized and remained unattached until 1853, when it was attached to Harrison County for revenue, election, and judicial purposes. It was fully organized and detached from Harrison County on April 3, 1854, and lost territory to Crawford County circa October 10, 1865.
- 1851Monona County created Monona created from Non-County Area 9 attached to Polk; Monona not fully organized, not attached. · Iowa Acts 1850-1851, ch. 9, sec. 25/p. 33
- 1853Changed Monona attached to Harrison "for revenue, election, and judicial purposes". · Iowa Acts 1852-1853, ch. 8, sec. 12/p. 23
- 1854Changed Monona fully organized, detached from Harrison. · Swisher, "Organization of Counties," 575
- 1865Lost territory Circa 10 October 1865, Monona lost to Crawford. · Crawford County Supervisors records, Book 1:309; Garver, "Establishment of Counties," 430
Land and parcels
What the maps cover in Monona
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 20,388 parcels from Monona County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 15 October 2026 -
Address points Missing
No public address points layer found for Monona 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
Monona 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.
County government
- County government
The official website of Monona County.
See your own lot on these maps
Open Monona 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 Monona County
- When was Monona County founded?
- Monona County was founded in 1851, formed from Polk County.
- What is the county seat of Monona County?
- The county seat of Monona County is Onawa.
- Is there an online parcel map for Monona County?
- Yes. Monona County publishes a parcel map of 20,388 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
- Has Monona County's boundary or name changed?
- Monona County was created in 1851 from Polk County. Since then the Atlas of Historical County Boundaries records 3 later changes, chiefly involving Harrison County and Crawford County.
- Is my lot in a flood zone?
- We do not have flood maps for Monona County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.
Nearby