Blog · October 14, 2026 · Pennsylvania
Using the Brentwood GIS Map
Most property questions near Castle Shannon start with a parcel lookup.
Main page: Allegheny County, PA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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For any lot around Pleasant Hills, the Brentwood GIS map lays out the outline, the owner of record and a parcel ID. What this Brentwood guide covers: where that map lives, how to search it, and what to double-check with records.
The official viewer behind the Brentwood GIS map
In most places the county maintains the parcel layer, which makes the Allegheny County ArcGIS parcel map the main source for lots in Brentwood.
Getting to the right map
Your first stop is the Allegheny County ArcGIS parcel map; it includes each tax parcel around Mount Oliver and Whitehall. For a home near Dormont, put in a street address, an owner's name or a parcel number, then pick the result to center the map on it. If the land is near Whitehall, a pop-up or side panel usually lists the owner of record, assessed acreage, the parcel number and sometimes recent sales.
Using it on a phone
The parcel map usually runs in a mobile browser, which helps when you're standing on land near Whitehall, so load it before you lose signal. A printout of the tract near Whitehall keeps working without signal.
Where the recorded documents are
The map is an index, not the title: deeds, plats and easements for land near Whitehall are filed with the Recorder of Deeds. Out toward Pleasant Hills, have ready the instrument number shown in the record panel so staff can find the deed fast.
Reading the legal description
Rural deeds near Dormont commonly use metes-and-bounds descriptions, which trace the boundary call by call. Subdivision lots in Mount Oliver usually use lot and block from a recorded plat instead, which is simpler to follow. Write down the legal description for the tract near Whitehall before you request a deed or survey.
Getting answers from the right desk
If the acreage or value on a parcel near Mount Oliver looks off belong with the county assessment office, which maintains the tax roll. Zoning, permits and septic questions near Whitehall need the planning or permitting office, depending on whether the land is inside town limits.
Printing and saving
Save a screenshot of the lot near Dormont and its record panel, which helps later when you ask the assessor or a title company.
Brentwood and the county around it
Brentwood lies within Allegheny County, Pennsylvania, so its parcels are on the county's map. With a lot near Baldwin, the municipality handles things like zoning, permits and utilities within town limits, and the county still keeps the parcel and deed records. Land beyond the city limits out by Baldwin often answers to county rules rather than the town's.
Browser tips
If the viewer stalls on a phone near Whitehall, try a desktop browser or clear the cache; links occasionally change, and our directory page keeps the current one.
A quick look at the area
Pittsburgh is the county seat, home to the main records offices. You'll also find Whitehall, Baldwin, Castle Shannon, and Mount Oliver, each with its own cluster of lots. Roughly 1,224,825 people call Allegheny County home (Census Bureau estimate, 2023) across roughly 730 square miles. Allegheny County was formed in 1788, and some chains of title near Castle Shannon are long. Places such as Allegheny River and Monongahela River help you orient on the aerial around Whitehall.
Search tips
Vacant ground near Pleasant Hills may lack an address, so zoom in from Interstate 376 and click the outline. For property near Mount Oliver, searching by parcel number never misses, and you'll find it on tax statements.
Layers worth turning on
Around Mount Oliver, layer lists often include municipal boundaries, floodplain and sometimes zoning; availability varies.
Limits of the parcel data
Parcel lines are drawn for taxes, not surveyed, so a tree line near Baldwin may sit a few yards off the line on screen. For acreage around Dormont, records update in batches, so a deed recorded last month might lag behind.
When a parcel crosses a boundary
Allegheny County borders Armstrong County, Beaver County, Butler County, Washington County, and Westmoreland County, and each of those keeps its own parcel map. A tract near the line by Pleasant Hills can be split across two assessors' files, so check the neighboring map before you assume the acreage. If the land is near Castle Shannon, our state page lists each bordering county map for Pennsylvania.
What the record panel tells you
The record for a parcel near Castle Shannon typically lists the owner of record, values and a legal description.
Frequently asked
Where else can I find maps of Brentwood?
In most cases, check the Brentwood website or ask city hall, while parcel data usually comes from the county.
How do I find who owns a lot near Dormont?
It depends, but the parcel record for a lot near Mount Oliver lists the owner of record; try variations if nothing comes up.
Do I need an account for the parcel map near Whitehall?
It depends, but the Allegheny County ArcGIS parcel map is free and opens without a login; some sites ask you to accept a disclaimer.
How often is the parcel map updated in Brentwood?
Out toward Dormont, updates come in batches.
Can I print the parcel map for land near Whitehall?
Some viewers offer PDF export, and it's worth keeping the parcel ID visible for land near Dormont.
Open the official Allegheny County, PA 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.