Blog · October 14, 2026 · Missouri
Using the Florissant Plat Map
Lots in Florissant trace back to recorded plats filed with the county.
Main page: St. Louis County, MO GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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When a deed near Dellwood says lot and block, look up the Florissant plat map it refers to. Covered here for Florissant: where plats are filed, how a plat differs from a parcel map, and what to look for on the sheet.
The Florissant plat map: start here
For a subdivision near Black Jack, the deed or parcel record often names the subdivision and plat reference; use it to request a copy.
The free map to start with
Go first to the St. Louis County ArcGIS parcel map; it includes each tax parcel around Calverton Park and Black Jack. If you only know roughly where the land is, follow Interstate 64 on the aerial until the lines appear, then click inside the one you want. For a home near Berkeley, the parcel card typically gives the owner of record, assessed acreage, the parcel number and in many cases the last transfer.
Where Florissant fits in
Florissant sits in St. Louis County, Missouri, so its parcels are on the county's map. Closer to Calverton Park, city or town hall handles matters such as zoning, permits and utilities inside its limits, while the county keeps the tax map. Land beyond the town limits out by Dellwood often answers to county rules rather than the town's.
Getting answers from the right desk
If the acreage or value on a parcel near Dellwood looks off go to the County Assessor, since that office keeps the assessment data. Zoning, permits and septic questions near Hazelwood go to planning, building or health offices, and the answer depends on jurisdiction.
Limits of the parcel data
Acreage on the record is an estimate; only a licensed surveyor sets the real corners on land around Ferguson. For a tract near Dellwood, owner names and values update on a schedule, so a deed recorded last month might lag behind.
St. Louis County in a few facts
Clayton holds the county offices, which is where the courthouse records live. You'll also find Calverton Park, Black Jack, Berkeley, and Hazelwood. Around 987,059 people live in St. Louis County (Census estimate, 2023) spread over about 508 square miles. St. Louis County was formed in 1812, which matters when you trace an old farm's title. Places such as Spanish Lake Park and Babler State Park make handy reference points on the map near Berkeley.
Two different maps
The tax map on the St. Louis County ArcGIS parcel map is a summary, whereas the plat carries surveyed dimensions.
Amended plats
Lots near Hazelwood can be combined or reconfigured by a replat, search the index for replats of the same subdivision; vacated streets or alleys also get recorded.
Field tips
Most viewers work in a phone browser, handy when you're parked on a road near Calverton Park, but coverage can be spotty out of town. A screenshot of the parcel near Berkeley with its ID is a good backup.
Land on the county line
St. Louis County touches Madison County, IL, Monroe County, IL, St. Clair County, IL, Franklin County, and Jefferson County; every one of them runs a separate parcel map. A tract near the line by Hazelwood may show up across two assessors' files, so look at the neighboring map before you assume the acreage. In and around Hazelwood, the Platbookmapper state page lists each neighboring county map for Missouri.
Deeds, plats and who keeps them
Before you sign anything, pull the recorded deed from the Recorder of Deeds; the parcel line is a drawing of it, whether the land is near Dellwood or elsewhere in the county. For a tract near Ferguson, have ready the document number listed on the parcel record to skip a name search.
Details on the Florissant plat map
Utility or drainage strips on a lot in Florissant stay with the land when it sells; check the plat notes and any covenants.
Getting a copy
Near Black Jack, some counties put plat images online, while others require a visit or a request; small fees are common.
Legal descriptions in Missouri
Missouri uses the Public Land Survey System, so rural legal descriptions near Berkeley cite section, township and range. Each section is nominally a mile square, about 640 acres, and a township holds 36 of them, though corrections make some sections near Berkeley odd-sized. Copy the legal description from the record for the parcel near Hazelwood when you talk to a surveyor.
Land outside a subdivision
Acreage around Berkeley outside a subdivision is often described by metes and bounds or survey description; look for a recorded survey for land near Black Jack.
Questions about the Florissant plat map
Are old plats online near Calverton Park?
The Recorder of Deeds can say what's available, including older subdivisions.
Where can I find the Florissant plat map?
Usually, the Recorder of Deeds keeps recorded plats.
Can I build on an easement in Florissant?
Out toward Black Jack, dashed lines often mark easements or building lines; read the plat notes.
Is a plat map a survey around Ferguson?
Good question; the plat near Hazelwood is recorded, while the GIS layer is an approximation; a surveyor ties it to the ground.
What is a parcel ID near Calverton Park?
The parcel ID identifies one tax parcel near Dellwood; you'll see it in the viewer and on tax statements.
Open the official St. Louis County, MO parcel map See it in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.