Blog · October 14, 2026 · Montana
The Jefferson County Plat Book: a Montana guide
Printed plat books and the free online map for owners around Whitehall.
Main page: Jefferson County, MT GIS & Parcel Viewer (official map link, Jefferson County facts and neighboring maps).
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Old copies of the Jefferson County plat book turn up at auctions and in kitchen drawers around Whitehall, and new ones are harder to track down. Below is how to track one down for Jefferson County, MT, and what the online map does better.
What's inside a county plat book
A plat book, sometimes called a land atlas, lists each township in Jefferson County as a page, with ownership blocks labeled by owner name and rough acreage. It's different from a recorded plat, which is the official survey drawing for a subdivision in Boulder filed with the county.
The county map you'll pair it with
For land around Boulder, open the Jefferson County ArcGIS parcel map (an Esri ArcGIS web map); it is the map Jefferson County itself publishes. Most people find their Jefferson County tract fastest by searching an address in Boulder, then clicking the outline. For a backup route to the map covering Boulder, our Jefferson County directory entry keeps the link current.
Where Jefferson County plat books turn up
Whether a current Jefferson County edition exists varies, so ask locally in Boulder before ordering; county offices commonly know if one is in print. Older editions are useful for family history around Whitehall, showing who held a farm decades ago.
Reading a Jefferson County atlas page
Plat book pages for Jefferson County typically include an index of owners, so you can find a family name near Basin without knowing the township. Acreage printed in a county atlas is rough; the deed and a licensed survey decide the real figure for a parcel near Basin. If you use a plat book for hunting permission near Boulder, recheck the titleholder on the county map first.
Old atlases and family history in Jefferson County
Names in an older Jefferson County atlas can lead you to the right deed in the grantor-grantee index for land near Jefferson City. Saving PDFs of the county map around Jefferson City gives you an offline reference when the signal drops.
Work and land use in Jefferson County
County Business Patterns counted 330 business establishments in Jefferson County for 2022, led by construction, accommodation and food services, and professional and technical services. Compared with national shares, Jefferson County leans toward utilities and specialty trade contractors, which shapes demand for land near Whitehall.
From Boulder to the back roads
Boulder is the county seat, and Whitehall are among the other towns on the county map. Unincorporated communities in the county, including Basin, Cardwell, and Clancy, show up as small groups of parcels along the roads. Jefferson County had an estimated 13,048 people in 2023 (Census Bureau), spread across about 1,657 square miles. Beyond the town lots in Whitehall, expect big rural parcels across the county.
Tracts that cross the Jefferson County line
Near the edge of the county, check the next map over: Broadwater County, Deer Lodge County, Gallatin County, Lewis and Clark County, and Madison County all border it. Every map bordering Jefferson County is listed on our Montana directory.
Recorded documents in Jefferson County, Montana
Deeds and plats behind the Jefferson County map are kept by the county's recording office; the official Jefferson County website names which office that is. Copy the parcel number and legal description from the county record before you request a deed for land near Boulder.
Current owners without a printed book
For current ownership, the free Jefferson County ArcGIS parcel map beats any printed book: owners update as deeds are processed, and you can click any parcel near Boulder. Pair the county map with a road atlas for the back roads near Whitehall.
Jefferson County, MT: common questions
Should I use the Jefferson County, Montana parcel map instead of a plat book?
For current owners near Boulder, yes; the Jefferson County ArcGIS parcel map updates as deeds are processed.
Can I buy a new plat book for Jefferson County, Montana?
It depends on if a publisher has a county edition in print; local offices in Basin typically know.
Can I use a plat book to find lot lines near Basin?
It lists rough ownership blocks; for lines near Basin, use recorded plats and surveys.
Is a plat book the same as a recorded plat for a lot in Basin?
No; a lot in Basin answers to its recorded plat, and the county atlas is just a reference.
Where can I find old plat books for Jefferson County, Montana?
Some libraries and historical societies keep older Jefferson County atlases; ask what's available near Boulder.
Open the official Jefferson County, MT parcel map Jefferson County 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.