Blog · October 14, 2026 · Montana
The Beaverhead County Plat Book: a Montana guide
Printed plat books and the free online map for owners around Argenta.
Main page: Beaverhead County, MT GIS & Parcel Viewer (official map link, Beaverhead 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.
A Beaverhead County plat book is the township-by-township atlas farmers, hunters and land buyers around Dillon have kept in the truck for generations. We'll cover what's in one, where Beaverhead County copies turn up, and how the county's free map fills the gaps.
What's inside a county plat book
Private publishers compile plat books from county records, so a county edition is a snapshot of who owned land near Lima the year it was printed. Deeds and recorded plats, not the atlas, still govern land near Dell in the county.
Search Beaverhead County parcels by owner, address or ID
The county's own public map is the Beaverhead County ArcGIS parcel map, built on an Esri ArcGIS web map, and it opens without an account for parcels in Argenta and the rest of the county. Use the search box for an address in Argenta or a parcel number, or simply zoom in and click a property near Lima. Bookmark our Beaverhead County page too; it tracks the official Montana link if it moves and lists the maps around Argenta.
Where Beaverhead County plat books turn up
Private publishers have printed plat books for many rural counties, but editions for Beaverhead County come and go; check at the courthouse, the extension office or a farm supply store in Lima. Older editions are useful for family history around Argenta, showing who held a farm decades ago.
Atlas details and limits
Plat book pages for Beaverhead County generally include an index of owners, so you can locate a family name near Dillon without knowing the township. Owner names in an older Beaverhead County edition may be decades out of date, so confirm on the county map before contacting anyone near Dell. Genealogists in Montana commonly pair an old Beaverhead County atlas with deed records to follow a farm through the generations.
Old atlases and family history in Beaverhead County
Farm families near Dillon commonly keep successive editions of the Beaverhead County plat book, which together show how ownership shifted over decades. Saving PDFs of the county map around Dell gives you an offline reference when the signal drops.
The Beaverhead County economy in brief
In 2022 the Census Bureau tallied 401 establishments in Beaverhead County; construction topped the list. Compared with national shares, Beaverhead County leans toward agriculture and forestry support services and accommodation (hotels, motels, RV parks and camps), which shapes demand for land near Lima.
From Dillon to the back roads
From Dillon, the seat of the county, the map spreads out to Lima. Unincorporated communities in the county, including Argenta, Dell, and Dewey, show up as small groups of parcels along the roads. Roughly 5,543 square miles of land and about 9,885 residents (2023 estimate) make up Beaverhead County. Beyond the town lots in Dillon, expect big rural parcels across the county.
Near the Beaverhead County line
A farm near the county line can carry separate records in Clark County, ID, Fremont County, ID, and Lemhi County, ID as well. Every map bordering Beaverhead County is listed on our Montana directory.
Beaverhead County land records
Deeds and plats behind the Beaverhead County map are kept by the county's recording office; the official Beaverhead County website names which office that is. Easements and access rights near Dillon live in recorded documents, so read the deed, not just the county map.
The free online alternative
For current ownership, the free Beaverhead County ArcGIS parcel map beats any printed book: owners update as deeds are processed, and you can click any property near Lima. Phone signal can be thin near Dell, so save the parcel IDs you need before you head out.
Beaverhead County plat book questions
Is a plat book the same as a recorded plat for a lot in Dillon?
No; a lot in Dillon answers to its recorded plat, and the county atlas is only a guide.
Can I use a plat book to locate lot lines near Dillon?
Only roughly; a Beaverhead County plat book is a reference, so a licensed survey decides the real line.
Where can I locate old plat books for Beaverhead County, Montana?
Check the library in Dillon, local historical groups and estate sales for older Beaverhead County editions.
Is the Beaverhead County, Montana online map better than a plat book?
For current owners near Lima, yes; the Beaverhead County ArcGIS parcel map updates as deeds are processed.
Can I buy a new plat book for Beaverhead County, Montana?
It depends on whether a publisher has a county edition in print; local offices in Dillon generally know.
Open the official Beaverhead County, MT parcel map Beaverhead 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.