Montana · FIPS 30043 · County seat: Boulder
Jefferson County, MT GIS & Parcel Viewer
Use this page to reach the official county parcel map for Jefferson County, Montana. The button below opens Jefferson County MT General Reference Map in a new tab, so you can look up parcels by address, owner or parcel number on the source site itself.
Open the Jefferson County parcel map ↗
Opens jeffcomt.maps.arcgis.com in a new tab. We link out and never embed or copy parcel data.
Map and county facts
| Official map | Jefferson County MT General Reference Map |
|---|---|
| Type | County-run map |
| Website | jeffcomt.maps.arcgis.com |
| Access | Free, no login (checked Oct 2026) |
| County seat | Boulder |
| Population | 13,048 (2023 Census Bureau estimate) |
| Land area | 1,657 sq mi |
| FIPS code | 30043 |
Where the parcel data comes from
This map is published by or for Jefferson County itself, so it reflects the local parcel layer rather than a third-party copy. When we tested the link in October 2026 it opened with no login and no fee.
How to use the Jefferson County viewer
- Open the official link; it loads in ArcGIS Map Viewer, Esri's standard web map.
- Zoom to the area you want, or enter an address in the search field.
- Select a parcel to see its pop-up details.
- Try the Basemap gallery for satellite views, and the Measure tool if you want a rough distance or area.
Have a tax bill handy? The parcel or account number on it is usually the fastest way to search.
Jefferson County by the numbers
Census Bureau figures put Jefferson County at about 13,048 people (2023 estimate) on roughly 1,657 square miles of land, which is about 7.9 residents per square mile. Among Montana's 56 counties, it is the 15th largest by population. Its county seat is Boulder.
Counties next to Jefferson County
If the property sits near a county line, the parcel may belong to a neighbor. These counties border Jefferson County:
- Broadwater County
- Deer Lodge County
- Gallatin County
- Lewis and Clark County
- Madison County
- Powell County
- Silver Bow County
Maps vs. surveys
Online parcel lines are drawn for tax and planning use. They can be off by several feet, so use a recorded plat or a licensed surveyor for fences, setbacks or a sale.