GIS

Polk County IA GIS provides online maps, parcel information, property-related geographic data, aerial imagery, political and service boundaries, elevation information, and downloadable spatial datasets for locations throughout Polk County. Residents, property owners, researchers, contractors, and other users can use the county’s GIS systems to locate tax parcels, compare aerial photography, review mapped boundaries, examine land-related information, and connect a selected property with records maintained by county offices. This page explains the main GIS systems, how their functions differ, what information to have ready before searching, which county offices maintain related records, and common mistakes that can lead to confusing results.

Polk County GIS Services

The main Polk County GIS maps and data portal is the county’s central entry point for mapping resources created or compiled by Polk County and participating local governments and agencies. It is broader than a single parcel viewer. The portal brings together interactive maps, applications, documents, spatial datasets, aerial imagery, boundaries, parks information, and other geographic resources.

Among the featured resources are the Polk County Map, County Supervisor Districts Map, Extreme Temp Centers Map, Parks Public Map, sex offender restriction mapping, and the Auditor Atlas website. Users can also search for GIS data by topic or browse datasets available for access or download.

The correct GIS resource depends on the task. A person trying to identify a parcel or examine zoning and flood layers may need the interactive county map. Someone researching ownership, recorded documents, assessed value, or taxation information may find Atlas more useful. GIS professionals looking for data to use in mapping software may instead need the dataset catalog or ArcGIS REST services.

Main Map and Atlas

The interactive Polk County Map provides a large collection of geographic layers in one map. Available information includes tax parcels, parcel labels, address information, political boundaries, zoning, land use, drainage districts, fire-rescue districts, school districts, sewer districts, flood information, wetlands, contours, aerial imagery, and other map layers.

Atlas serves a different purpose. The Polk County Auditor Atlas starts with a location or property search and then connects the selected location with categories such as Ownership Information, Land Records, and Valuation & Taxation. Atlas can therefore be more practical when the goal is to research one parcel rather than display many GIS layers across a larger geographic area.

These systems overlap, but they are not interchangeable. The county map emphasizes geographic visualization and layers. Atlas emphasizes a selected property and links between that location and related county records. Choosing between them based on the task can reduce unnecessary searching.

Property and Parcel Mapping

Tax parcels are among the most useful features of Polk County GIS. The county map contains a Tax Parcels layer as well as several Auditor-related layers that provide geographic context for properties. These include parcel labels, Geo Parcel Number, historic District Parcel Number, address numbers, streets, section-township-range information, government lots, subdivisions, subdivision lots, condominium units, and other parcel points.

Users who want to focus specifically on cadastral information can use the county’s parcel and cadastral GIS search. This narrows the GIS portal toward parcel-related resources rather than requiring users to browse the entire collection of maps, documents, and datasets.

Parcel Numbers and Addresses

A parcel number and a street address should not be treated as the same identifier. A street address describes a situs location, while a parcel number identifies a tax parcel. The county GIS systems display both types of information because a property search may involve several related geographic and administrative records.

Atlas allows a parcel search by parcel number, owner, or address. Before beginning a property search, it is useful to have one or more of those identifiers available. A complete address can help narrow a location, while a parcel number provides a direct way to identify the tax parcel when it is already known.

Atlas may also display other associated situs addresses for a selected parcel. That can matter when a parcel has more than one address associated with it or when the address a user expects does not appear as the primary displayed location.

Historic Parcel Identifiers

The interactive county map distinguishes between Geo Parcel Number and District Parcel Number, with District Parcel Number identified as historic. Users comparing older property documents with current GIS information should pay attention to which identifier appears in the material they are reviewing.

An older record may therefore contain an identifier that does not look like the parcel number shown prominently in a current map view. Rather than assuming the property has been entered incorrectly, compare the available parcel-related layers and confirm that the selected geographic location is the intended property.

Using Auditor Atlas

Atlas provides a defined workflow for researching a location. The first step is selecting a location directly on the map or using the Search function. The search options include Parcel, Subdivision, and Condo, allowing the system to handle several common types of property-related searches.

Parcel Search Options

For a parcel search, Atlas accepts a parcel number, owner, or address. After entering the available information, users can select the appropriate result and move to the location on the map. A subdivision can instead be searched by subdivision name, while a condominium search uses the condo name.

Once a location has been selected, Atlas organizes related information into three principal categories:

Ownership Information for information connected with the selected property and ownership records.

Land Records for property-related records such as subdivision information, recorded documents, and plats of survey when applicable.

Valuation & Taxation for assessment and taxation information connected with the selected location.

Users can also open the Layers control, expand the Atlas groups and subgroups, and select additional geographic information to display. This makes Atlas useful when a property record needs to be viewed together with mapped information rather than as text alone.

Land Records in Atlas

For the selected location, Atlas may display information such as the parcel, available address information, mailing address, tax description, acreage, subdivision, condominium information, plats of survey, and recorded documents. The system also provides connections to records maintained by other county offices.

The tax description shown in Atlas is specifically identified as not to be used on legal documents. Users should therefore avoid copying the displayed tax description into a deed, contract, filing, or other legal document on the assumption that it is a legal description.

When subdivision information applies, Atlas can provide access to Recorder subdivision plats and Auditor subdivision plats. For plats of survey associated with the selected location, users can follow the available record to view a copy through the Polk County Recorder’s system. Recorded documents associated with a tax parcel can likewise be connected to Recorder records through Atlas.

Property transfers are handled separately. Atlas states that Polk County property transfers can be searched through the Polk County Auditor Real Estate Transfer Index Search. This distinction is useful because a map display, a recorded document, and a transfer index entry serve different purposes even when all three relate to the same property.

Assessment and Tax Records

GIS can help users locate a property and connect geographic information with assessment and taxation records, but responsibility for those records is divided among county offices. Atlas identifies the Polk County Assessor as the office responsible for property classifications and assessed values.

Mailing addresses are maintained by the Polk County Treasurer’s office. This means that a mailing-address issue should not be treated as a GIS mapping correction simply because the mailing information appears while viewing a parcel in Atlas.

Users should distinguish at least three types of property information:

The mapped parcel and its geographic location in GIS.
Property classification and assessed value maintained by the County Assessor.
Mailing address and taxation-related information associated with the Treasurer’s records.

A discrepancy in one category does not necessarily mean another category is wrong. Identifying which field needs attention is the first step toward contacting the office that maintains that record.

Boundaries and District Layers

Polk County GIS contains much more than property outlines. The county map includes political, administrative, service, and tax-related boundaries that can help users determine how a location relates geographically to different jurisdictions or districts.

The available boundary layers include Polk County townships, corporate limits, tax-related districts, drainage districts, fire-rescue districts, school districts, sanitary sewer districts, SSMID areas, TIF areas, subdivisions, and other mapped features. Users looking specifically for this type of information can browse the county’s boundary-related GIS resources.

Political District Mapping

The GIS portal also features a County Supervisor Districts Map showing County Supervisor districts and related information. This is separate from simply displaying tax parcels or city limits. Users researching a particular property should make sure the boundary layer they are viewing corresponds to the type of district they actually need.

Layer names can look similar when several boundaries cross the same area. Turning off unrelated layers can make it easier to determine which line belongs to a township, corporate limit, school district, tax district, or another mapped jurisdiction.

Zoning and Land Use

The interactive map includes County Zoning and Land Use categories, including Unincorporated Zoning and Unincorporated Land Use. These layers can be useful for viewing mapped zoning and land-use information in parts of the county covered by those datasets.

Users should avoid assuming that every line or color shown on the map represents a property boundary. Parcel lines, zoning polygons, political boundaries, flood zones, and other layers may overlap. When several layers are active at once, reviewing the layer list and turning unnecessary information off can make the map easier to interpret.

Polk County Public Works is one of the agencies identified in the map’s source information, and the county map includes Public Works-related geographic content. Questions about records or services maintained by Public Works should be directed to that office rather than assuming the GIS portal itself changes the underlying departmental record.

Flood and Wetland Mapping

The county map contains several flood-related layers, including FEMA National Flood Hazard Layer information, Base Flood Elevations, cross sections, levees, water lines, FIRM panels, flood hazard zones, and water areas. It also includes National Wetlands Inventory information, including linear and polygon features.

These layers allow users to compare a parcel or location with mapped flood and wetland information. Because several flood-related datasets may be displayed at the same time, users should identify the individual layer being viewed rather than treating all flood information as a single dataset.

The map identifies sources that include the Federal Emergency Management Agency and the Iowa Department of Natural Resources alongside Polk County and other public agencies. The GIS display is therefore a geographic compilation rather than a single record created entirely by one county department.

Elevation and Contour Data

Elevation information is another significant part of Polk County GIS. The interactive map includes 2-foot contours from 2020 as well as 10-foot, 50-foot, and 100-foot contour layers. It also provides 2020 and 2010 lidar hillshade layers.

Different contour intervals serve different viewing purposes. A dense contour layer may provide more detailed representation of terrain, while a wider interval can make larger elevation patterns easier to see. Turning on several contour datasets simultaneously can make the map difficult to read, so users should select the level of detail appropriate for the location and scale being examined.

Aerial Imagery Archives

Polk County GIS provides a particularly extensive collection of aerial imagery. The interactive map includes annual aerial layers for many recent years as well as historical imagery reaching back several decades.

Users can browse the county’s aerial imagery GIS collection when imagery is the primary subject of the search. The map lists recent aerials from 2025 backward through earlier annual collections, along with imagery from the 1970s, 1960s, 1950s, and 1930s.

Historical imagery can help users visually compare how roads, development, land patterns, and other physical features appeared at different times. An aerial image should not, however, be confused with an official parcel record or recorded land document. Imagery depicts physical conditions captured at a point in time, while parcel and land-record systems contain separate administrative information.

Comparing Different Years

When comparing historical imagery, users should confirm which year is active before drawing conclusions from what appears on the map. The county map contains numerous similarly named aerial layers, so it is easy to leave more than one imagery source active or to mistake one year for another.

A practical approach is to display the parcel or location first, activate one aerial layer, note the year, and then switch to another year for comparison. Keeping other layers to a minimum can make physical changes easier to recognize.

GIS Data Downloads

The GIS portal is also designed for users who need spatial data rather than only an interactive map. The county provides a dedicated GIS dataset catalog for locating datasets that can be accessed or downloaded.

The main portal groups data around subjects that include parcels, boundaries, aerial imagery, and parks. The portal also states that leaving its search box empty will return all data, which can be useful when a user wants to browse the complete catalog rather than search for a particular term.

ArcGIS REST Services

Technical users working with GIS software or web mapping applications can also access the county’s ArcGIS REST Services directory. The directory contains folders for areas such as aerial imagery, Auditor data, Conservation, Elections, Elevation, Health, Public Works, Sheriff, Treasurer, Utilities, and other county functions.

The REST directory is different from the public parcel-search interface. It is organized around GIS services such as MapServer resources and agency folders rather than a step-by-step property lookup. Users seeking an owner name or a single parcel will generally find Atlas or the county map more directly suited to that task.

Map Changes During 2026

The existing Polk County Map states that it will be replaced at the end of 2026. Users who rely on the current interface for recurring work should be prepared for changes to the map environment, layer controls, or workflow when the replacement is introduced.

The current map identifies its data as refreshed September 4, 2026, version 1.1. That date should not be interpreted as meaning every individual record or source layer was originally created or updated on that same date. The map includes datasets from different agencies and time periods, including historical aerial imagery and earlier lidar products.

GIS Data Limitations

Polk County places a clear limitation notice on its GIS portal and mapping applications. The county states that the information was compiled for government purposes and makes no warranties, expressed or implied, concerning its accuracy, completeness, reliability, or suitability for a particular use. The county also states that the data may change at any time.

That limitation is especially relevant when a user is comparing map information with official records. A GIS boundary displayed on a screen, a tax description in Atlas, an assessment record, a recorded document, and a property-tax record are different types of information maintained for different purposes.

For decisions requiring an official county record, identify the office responsible for that record instead of relying solely on the map display. The GIS system is useful for locating, visualizing, and connecting information, but it should not be treated as a substitute for every underlying departmental record.

Common GIS Search Mistakes

Searching the Wrong System

A common problem is trying to make one GIS application perform every property-record function. The county map is strongest for geographic layers and visual comparison, while Atlas is designed around selecting a property and viewing connected ownership, land-record, valuation, and taxation information. The dataset catalog and REST services serve still different purposes.

Confusing Parcel and Address Data

A street address should not automatically be treated as a parcel identifier. If an address search produces an unexpected result, compare the parcel number, property location, and associated situs addresses before assuming the map is incorrect.

Using Tax Descriptions Legally

Atlas labels its tax description as information that is not to be used on legal documents. Users who need recorded land information should instead follow the relevant Recorder records available for the selected parcel.

Mixing Record Responsibilities

GIS displays information originating from several county functions. Property classifications and assessed values are determined by the County Assessor. Mailing addresses are maintained by the Treasurer. Recorded documents and survey records connect with the County Recorder. Property transfers can be searched through the Auditor’s Real Estate Transfer Index. Knowing which office owns the underlying record helps prevent requests from being sent to the wrong department.

Leaving Too Many Layers Active

The county map contains a large number of overlapping layers. Parcel lines, zoning, flood hazards, wetlands, political districts, service districts, contours, and aerial imagery can become difficult to distinguish when displayed together. For a clearer map, keep the parcel or location visible and activate only the additional layers needed for the question being researched.

Preparing for a GIS Search

Users can reduce searching time by collecting the property or location information already available before opening the map. Depending on the task, useful information may include:

A complete property address.

The parcel number, if known.

The property owner name for an Atlas parcel search.

A subdivision name when researching a subdivision.

A condominium name for a condo search.

The approximate location when selecting directly from the map.

The specific type of information needed, such as parcels, boundaries, aerial imagery, zoning, flood data, assessment information, or recorded land documents.

After locating the correct property, compare the displayed parcel with surrounding streets and geographic features before relying on related information. If the task concerns a particular county record, move from the GIS display to the office that maintains that record rather than treating the map as the final source for every property-related question.

GIS-Related County Offices

Polk County Assessor
111 Court Ave., Room 195
Des Moines, IA 50309
(515) 286-3014

Polk County Auditor
Administration Building
111 Court Avenue, Room 230
Des Moines, IA 50309
(515) 286-3080

Polk County Recorder
Polk County Administration Building
111 Court Avenue, Suite 250
Des Moines, IA 50309
515-286-3160

Polk County Public Works
5885 NE 14 Street
Des Moines, IA 50313
(515) 286-3705

Polk County Treasurer
Polk County Administration Building
111 Court Avenue, Room 154
Des Moines, IA 50309
515-286-3060

GIS FAQs

Can I reopen the map where I left off?

The Polk County Map includes an App State feature that can restore the map extent and layer visibility from a previous session. This is useful when you have already zoomed to a particular neighborhood or rural area and selected several layers for comparison. If the saved state is available, use the restore option instead of rebuilding the same map view manually. Keep in mind that changes to the application or browser storage may affect whether a previous state remains available.

Why does the GIS portal show a sign-in option?

The county’s GIS portal includes a sign-in function because it is built on Polk County’s ArcGIS Enterprise system. Publicly listed maps, applications, documents, and datasets can be reached through the Polk County GIS portal. A sign-in prompt does not necessarily mean that the public resource you selected requires an account. If a specific item asks for credentials rather than opening normally, return to the public portal and choose another publicly available map or dataset.

How can I find a specialized county map?

Do not limit your search to the primary county map. The GIS portal separates resources into Apps & Maps, Documents, and data collections, and it also publishes specialized applications for subjects such as parks, supervisor districts, temperature centers, and other county functions. When searching the portal, use a subject term that closely matches the information you need. If you want to browse broadly, the county notes that leaving the GIS data search box empty will return all available data results.

Can mapping software connect directly to county services?

Yes. Polk County publishes an official ArcGIS REST Services Directory with folders for functions including Auditor, Elections, Elevation, Public Works, Sheriff, Treasurer, Utilities, Water Quality, aerial imagery, and other county programs. These endpoints are intended for users working with GIS software, web maps, or applications that can consume ArcGIS services. Check the individual service type and available interface before adding it to a project.