Montana · FIPS 30069 · County seat: Winnett
Petroleum County, MT GIS & Parcel Viewer
Petroleum County, Montana parcel data lives on Montana Cadastral (Montana State Library). Open it below in a new tab, then use the short steps on this page to find a property fast.
Open the Petroleum County statewide map ↗
Opens svc.mt.gov in a new tab. We link out and never embed or copy parcel data.
Petroleum County at a glance
| Official map | Montana Cadastral (Montana State Library) |
|---|---|
| Type | Statewide map (covers all of Montana) |
| Website | svc.mt.gov |
| Access | Free, no login (checked Oct 2026) |
| County seat | Winnett |
| Population | 554 (2023 Census Bureau estimate) |
| Land area | 1,656 sq mi |
| FIPS code | 30069 |
Who runs this map
The link goes to a statewide map (Montana Cadastral (Montana State Library)). It shows parcels for Petroleum County along with the rest of Montana. Statewide parcel layers are usually stitched together from county files, so the newest splits or sales may show up on the county's own records first. As of our October 2026 test, anyone could open it without signing in or paying.
Searching for a parcel, step by step
- Open Montana Cadastral (Montana State Library) in a new tab and zoom to Petroleum County (around Winnett).
- Type a street address into the search box, or click directly on a parcel.
- Review the parcel attributes; field names vary by state.
- Confirm anything important with the county assessor, since the statewide layer is a compiled copy.
Many parcel sites expect owner names last name first. If a full name finds nothing, try just the surname.
About Petroleum County
Census Bureau figures put Petroleum County at about 554 people (2023 estimate) on roughly 1,656 square miles of land, which is about 0.3 residents per square mile. That makes it the least populous of Montana's 56 counties. Winnett serves as the county seat.
Neighboring counties
Petroleum County shares a border with the counties below. Each link has its own official map:
A note on accuracy
Keep in mind that a GIS parcel layer is a tax map, not a survey. For exact boundaries, look at the recorded deed and plat or hire a licensed land surveyor.