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    ATLAS · STATE·MO

    Missouri county
    parcel REST APIs.

    2 counties indexed. ArcGIS FeatureServer and MapServer URLs, with supported search fields per layer.

    Counties indexed in this state, with endpoint counts, supported fields, and status.
    CountyEndpointsSearchable fieldsStatusAction
    Jackson County1Parcel Identification Number · Owner Name · Property Full Address LIVEOPEN
    St. Louis County1Parcel Locator Number · Parent Locator · Owner Name +6 LIVEOPEN

    About Missouri county parcel data

    State overview

    Missouri has 114 counties plus the City of St. Louis, which is an independent city not part of any county — one of only a handful of such arrangements in the US. Each county has an elected County Assessor. The Missouri Spatial Data Information Service (MSDIS), hosted at the University of Missouri, is the state GIS clearinghouse, but it does not maintain a live statewide parcel REST endpoint; its parcel holdings are periodic bulk exports. County GIS departments publish REST layers independently, with wide variation in attribute depth and update frequency. St. Louis County — the suburban county surrounding but not including the city — operates a capable public MapServer with owner names, property class, full address, and assessed value. The City of St. Louis is a separate entity (FIPS 29510) with its own GIS; do not assume St. Louis County endpoints cover city-of-St. Louis parcels.

    Regional coordination

    MSDIS (msdis.missouri.edu) is the nominal statewide GIS authority but is an academic clearinghouse, not a real-time aggregation platform. Missouri county GIS directors operate through the Missouri Association of County Information Technology Directors (MACITD) and the ESRI Missouri User Group, but there is no coordinated statewide parcel REST program. The Missouri State Tax Commission oversees assessment standards and equalization across counties, setting the framework within which County Assessors operate, but does not publish parcel spatial data. Kansas City straddles Jackson County and several other counties (Clay, Platte, Cass) — queries for Kansas City parcels may require hitting multiple county endpoints. St. Louis metro parcel research similarly requires separate queries to St. Louis County (maps.stlouisco.com) and the City of St. Louis (stlouis-mo.gov GIS).

    Common data quirks

    City of St. Louis vs. St. Louis County: two separate entities

    St. Louis County (FIPS 29189, county seat Clayton) and the City of St. Louis (FIPS 29510, an independent city) are separate legal and GIS entities. St. Louis County covers the suburban ring — Clayton, Chesterfield, Webster Groves, Ladue, Kirkwood, Florissant — but not the city of St. Louis itself. The atlas covers St. Louis County via maps.stlouisco.com; if your project covers parcels within the city boundaries, you need the separate City of St. Louis GIS endpoint. This distinction trips up out-of-state researchers who assume 'St. Louis County' means the metro area. The St. Louis metro is split across two FIPS codes and two GIS systems.

    St. Louis County uses LOCATOR as the parcel identifier, not APN

    St. Louis County's public parcel layer uses LOCATOR as the primary parcel identifier. The LOCATOR field encodes a county-specific numbering scheme distinct from the APN or PIN conventions used in other states. PARENT_LOC tracks parent parcels (useful for tracking subdivision splits). MUNYCODE identifies the specific municipality within the county. SCHSUB is the school subdivision code. TAXCODE and TAXYR are present for tax-year context. TWPNAME identifies the township. These fields reflect the complex layering of taxing districts within St. Louis County, where school, fire, water, and other special districts each levy separately on the same parcel.

    Kansas City parcels span multiple counties

    Kansas City, Missouri spans portions of Jackson County (the primary county, containing most of KC proper), Clay County (north), Platte County (northwest), and Cass County (south). There is no single REST layer for 'Kansas City parcels.' Jackson County runs a public GIS, but the portions of Kansas City in Clay or Platte counties require separate endpoint queries to those county GIS servers. If you are building a KC metro parcel tool, plan for multi-county endpoint aggregation. This multi-county city configuration is common in Missouri given its 114 counties and the state's history of home rule city charters.

    Key counties

    St. Louis County

    St. Louis suburban county (NOT the City of St. Louis). AGS_Parcels/MapServer/0 at maps.stlouisco.com exposes LOCATOR, OWNER_NAME, PROP_ADD, OWN_ADD/CITY/STATE/ZIP, PROPCLASS, TOTASSMT, APPLANDVAL, APPIMPVAL, MUNYCODE, SCHSUB, and TWPNAME. 30+ fields; owner queries confirmed live.

    Common search patterns

    St. Louis County owner search: ?where=UPPER(OWNER_NAME)+LIKE+UPPER('%25SMITH%25')&outFields=LOCATOR,OWNER_NAME,PROP_ADD,PROP_ZIP,OWN_CITY,PROPCLASS,TOTASSMT&returnGeometry=false&f=json&resultRecordCount=10 (base: maps.stlouisco.com/hosting/rest/services/Maps/AGS_Parcels/MapServer/0). Property address search: ?where=UPPER(PROP_ADD)+LIKE+UPPER('%25LILAC%25')&outFields=LOCATOR,OWNER_NAME,PROP_ADD,TOTASSMT&returnGeometry=false&f=json. LOCATOR lookup: ?where=LOCATOR='<value>'&outFields=*&returnGeometry=false&f=json. Municipality filter (e.g. Clayton): ?where=MUNYCODE='005'+AND+UPPER(OWNER_NAME)+LIKE+UPPER('%25SMITH%25')&outFields=LOCATOR,OWNER_NAME,PROP_ADD&returnGeometry=false&f=json.

    Related articles

    Last updated 2026-05-24.

    Questions, with answers

    Missouri parcel REST API — common questions

    Which Missouri counties publish a public parcel ArcGIS REST API?

    2 Missouri counties are indexed in the UrbanKit atlas with verified public REST endpoints: Jackson and St. Louis. Each exposes an owner-name field you can search directly on the public layer.

    How do I search Missouri parcels by owner name?

    Jackson and St. Louis expose an owner-name field on the public REST layer. Jackson, for example, uses the OWNER field — a case-insensitive search is ?where=UPPER(OWNER)%20LIKE%20UPPER('%25SMITH%25')&outFields=*&f=json. Open a county's page here for its full field list and a ready-to-run sample query.

    What is the ArcGIS REST URL for parcels in Jackson, Missouri?

    Jackson publishes parcels at https://gis.mijackson.org/countygis/rest/services/RealEstate/RealEstateParcels/FeatureServer/0 — a FeatureServer (layer 0). It indexes by Parcel Identification Number, Owner Name, and Property Full Address. Owner-name search: UPPER(OWNER) LIKE UPPER('%25SMITH%25').

    Do Missouri parcel layers use ArcGIS FeatureServer or MapServer?

    Both. Missouri uses a mix: Jackson publish ArcGIS FeatureServer layers, while St. Louis use MapServer. Both support /query, so the same owner, parcel-ID, and address lookups work against either.

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