Blog · October 14, 2026 · Montana
The Broadwater County Plat Book and the online parcel map
For property near Radersburg, plat books show ownership by township; the parcel viewer shows it today.
Main page: Broadwater County, MT GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Looking for a Broadwater County plat book? It's a printed atlas of landownership, usually by township, useful for farms near Townsend. This Broadwater County guide covers: how the atlas is organized, where to look for printed copies, and how the county viewer fills the gaps.
Getting started with the Broadwater County plat book
Around Wheatland, plat books are commercial atlases, that map ownership across the countryside, page by page across the county.
Getting to the right map
Your first stop is the Montana Cadastral; it includes every assessed parcel from Helena National Forest to Spokane Creek. When a rural tract has no street number, pan along the nearest road and click the parcel itself, and that holds around Helena National Forest too. For a tract near Canyon Ferry Lake, The record panel typically gives the owner of record, assessed acreage, the parcel number and often a sale date.
The paper trail behind a parcel
For land near Spokane Creek, The map is an index, not the title: deeds, subdivision plats and easements for parcels in the county are filed with the County Clerk and Recorder. If the land is near Spokane Creek, bring the document number shown in the record panel to skip a name search.
Limits of the parcel data
With a lot near Spokane Creek, acreage on the record is an assessed number; only a licensed surveyor can set the real lines on the ground. If the land is near Townsend, records update in batches, so a deed recorded last month may not show yet.
Next door to Broadwater County
The county borders Gallatin County, Jefferson County, Lewis and Clark County, and Meagher County, and each of those keeps its own parcel map, at least around Townsend. Ground near The Silos that runs to the line can be split across two assessors' files, so open the adjacent map before you assume the acreage. With a lot near Toston, The Platbookmapper state page lists each neighboring county map for Montana.
Buying or borrowing a copy
Not every county has a current edition, check with local offices and farm stores near Helena National Forest.
Using the parcel viewer instead
With a lot near Spokane Creek, The Montana Cadastral is updated more often than any atlas, across the county.
Places you'll see on the map
Townsend holds the county offices, which is where the courthouse records live. You'll also find Radersburg, Spokane Creek, The Silos, and Toston. About 8,032 people live in Broadwater County (Census estimate, 2023) on about 1,192 square miles. The county was organized in 1897, and some chains of title near Toston are long. Features like Canyon Ferry Lake and Helena National Forest make handy reference points on the map.
Using it on a phone
Most viewers work in a phone browser, which helps when you're standing on land near The Silos, so load it before you lose signal. A printout of the tract near Canyon Ferry Lake is a good backup.
Common uses
Buyers and seed dealers around The Silos rely on them for a big-picture view of who owns what.
Printing your own
Print parcel views near Spokane Creek township by township to build your own up-to-date atlas.
Reading the legal description
Montana follows the Public Land Survey System, so rural legal descriptions near Canyon Ferry Lake cite section, township and range. Each section is nominally a mile square, about 640 acres, with 36 sections to a township, though sections near Helena National Forest can be irregular. Keep the legal description for land near The Silos before you request a deed or survey.
Plat book vs. recorded plat
If the land is near Townsend, don't confuse the atlas with a recorded subdivision plat: the recorded plat at the County Clerk and Recorder is a legal document, and the atlas is just a guide.
Who handles what
If the acreage or value on a parcel near The Silos looks off go to the Montana Department of Revenue, the office behind the parcel record. Building or septic questions for a lot near Helena National Forest go to planning, building or health offices, town or county, depending on location.
Quick answers
How do I research old landowners in Broadwater County?
Around Canyon Ferry Lake, some older atlases have been digitized; call ahead.
How accurate are plat book acreages around Helena National Forest?
For a parcel near Toston, plat book acreage and lines are approximate; they're good for orientation.
Is a plat book legal proof for land near Radersburg?
For a home near Radersburg, recorded plats are legal documents at the County Clerk and Recorder, and plat books are references.
Who sells plat books in Broadwater County?
For most people, the extension office or courthouse near Townsend usually knows; ask local offices.
What's a legal description in Broadwater County?
With a lot near Spokane Creek, it's the formal description of the land in the deed, and the parcel record often summarizes it.
Open the official Broadwater County, MT 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.