Blog · October 14, 2026 · Wisconsin
Reading the Mequon Plat Map for a lot
Lots in Mequon trace back to recorded plats filed with the county.
Main page: Ozaukee County, WI GIS & Parcel Viewer (official map link, county facts and neighboring maps).
Platbookmapper is an Amazon Associate. If you buy through an Amazon link on this page, we earn a commission. The link is a product, not the county map.
When a deed near Thiensville says lot and block, you'll need the Mequon plat map to make sense of it. Covered here for Mequon: where plats are filed, how a plat differs from a parcel map, and the details that matter to buyers.
Who keeps the Mequon plat map
For land around Port Washington, look for the plat book reference on the parcel record; that makes the request quick.
The viewer Ozaukee County publishes
Parcels around Cedarburg can be looked up on the Ozaukee County parcel viewer, free to use and open without a login. For a home near Port Washington, put in a street address, an owner's name or a parcel number, and the matching parcel lights up. For a parcel near Cedarburg, write down the parcel ID before closing the panel; every clerk in the county uses it to find the file.
Offices that can help
If the acreage or value on a parcel near Bayside looks off are handled by the county real property listing office, since that office keeps the assessment data. Questions about what you can build around Grafton need the planning or permitting office, town or county, depending on location.
Amended plats
Lots near Port Washington can be combined or reconfigured by a replat, so check for later filings; street vacations near Bayside show up in the records too.
City limits and county records
Mequon lies within Ozaukee County, Wisconsin, so its parcels are on the county's map. Closer to Port Washington, city or town hall handles things like zoning, permits and utilities within town limits, but the county runs assessment and recording. Lots just outside the town limits out by Cedarburg often falls under county rules instead.
Land on the county line
Ozaukee County touches Muskegon County, MI, Oceana County, MI, Milwaukee County, Sheboygan County, and Washington County, all with their own assessor records. A tract near the line by Grafton may show up in two county records, so look at the neighboring map too. With a lot near Port Washington, our state page links every neighboring county map across Wisconsin.
The paper trail behind a parcel
The map is an index, not the title: recorded deeds, plats and easements covering ground around Grafton are filed with the Register of Deeds. For property near Bayside, have ready the book and page listed on the parcel record so staff can find the deed fast.
A word on accuracy
Tax maps are drawn for assessment, not surveyed, so a tree line near Bayside often sits a few yards off the line on screen. For a tract near Saukville, owner names and values update on a schedule, so a deed recorded last month might lag behind.
Field tips
The parcel map usually runs in a mobile browser, which helps when you're standing on land near Saukville, but coverage can be spotty out of town. A screenshot of the parcel near Thiensville with its ID keeps working without signal.
Plat map vs. parcel map
When the two disagree for a lot near Cedarburg, the recorded plat and a survey control.
Land outside a subdivision
Rural land near Thiensville that was never subdivided is often described by metes and bounds or survey description; the deed and any recorded survey describe it instead.
Legal descriptions in Wisconsin
Wisconsin follows the Public Land Survey System, so deeds around Port Washington reference sections and townships. Each section is nominally a mile square, about 640 acres, and a township holds 36 of them, though corrections make some sections near Port Washington odd-sized. Keep the legal description for land near Thiensville for any title or survey request.
Getting your bearings
Port Washington is the county seat, which is where the courthouse records live. You'll also find Thiensville, Bayside, Cedarburg, and Grafton, each with its own cluster of lots. Around 93,460 people call Ozaukee County home (Census Bureau estimate, 2023) across roughly 233 square miles. Ozaukee County was formed in 1853, so old deeds can run back a long way. Features like Lake Michigan and Lion's Den Gorge Nature Preserve help you orient on the aerial around Saukville.
What a plat shows
For a tract near Bayside, the sheet usually includes lot and block numbers, dimensions and bearings, street rights-of-way and easements.
Ordering the Mequon plat map
For land near Grafton, some counties put plat images online, while others require a visit or a request; copy fees are usually small.
Mequon: common questions
What do the dashed lines on a plat mean around Grafton?
Building on an easement near Saukville is generally restricted; ask planning staff if unsure.
Are old plats online near Thiensville?
Good question; older plats near Grafton may be on film or paper, including older subdivisions.
Can lots near Port Washington be combined?
Generally, lot splits in Mequon go through the planning office.
What is a lot and block description in Mequon?
With a lot near Grafton, lot and block refer to a numbered lot within a block on a recorded subdivision plat.
What's the tax parcel number used for around Bayside?
It's the number the county real property listing office uses to track a tract near Saukville; you'll see it in the viewer and on tax statements.
Open the official Ozaukee County, WI 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.