When was Sanders County founded?

Sanders County was founded in 1906, formed from Missoula County, and named after Wilbur F. Sanders.

What is the county seat of Sanders County?

The county seat of Sanders County is Thompson Falls.

Is there an online parcel map for Sanders County?

Yes. A public source publishes a parcel map of 15,527 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Sanders County's boundary or name changed?

Sanders County was created in 1906 from Missoula County. Since then the Atlas of Historical County Boundaries records 3 later changes, chiefly involving Flathead County, Lincoln County and Missoula County.

Who issues building permits in Sanders County?

The county's page on building permits: Forms & Permits. Inside a city or town, ask that city first.

Who issues septic and well permits in Sanders County?

The county's page on septic systems and wells: Public Health.

Is my lot in a flood zone?

We do not have flood maps for Sanders County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Sanders County, Montana: parcels, history and offices

Where it is

Sanders on the map of Montana

Montana has 56 counties and county equivalents, each with its own records office. Shapes with a page are links.

Counties of Montana · Sanders highlighted

History

Formed in 1906 from Missoula County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Sanders County was created from Missoula County on March 1, 1906, following an act passed on February 7, 1905, and was named after Wilbur F. Sanders. The county exchanged boundary land with Missoula County in 1911 and with Flathead County in 1913 when boundaries were adjusted to run on federal land survey lines, then gained territory from Lincoln County in 1913.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1906
Sanders County created Sanders created from Missoula. Act passed 7 February 1905; took effect 1 March 1906.
from Missoula
1 March 1906 · Mont. Laws 1905, 9th leg., ch. 9/pp. 18-24
1911
Exchanged territory Sanders exchanged with Missoula.
with Missoula
25 February 1911 · Mont. Laws 1911, 12th leg., ch. 54/pp. 90-91
1913
Exchanged territory Sanders exchanged with Flathead when boundary was adjusted to run on federal land survey lines.
with Flathead
28 February 1913 · Mont. Laws 1913, 13th leg., ch. 42/pp. 58-59
1913
Gained territory Sanders gained from Lincoln.
from Lincoln
1 March 1913 · Mont. Laws 1913, 13th leg., ch. 46/pp. 66-67

Land and parcels

What the maps cover in Sanders

Who publishes each layer, how good it is, and when we last checked.

Parcels Good enough

Lot lines and tax-map numbers for 15,527 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
checked 14 October 2026
Address points Official

One point per address, 9,954 in all from Montana State Library.
edited 13 October 2026 · checked 14 October 2026
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Sanders by the Census

Population

12,400 2020 Census count

Housing units

6,800 2020 Census count

Land area

2,760 square miles

Water area

30 square miles

People per sq mi

4 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Who to ask before you build, dig or sell

Official county pages only. We link to them; we do not copy them, because they change.

Inside a city or town, permits usually come from that city rather than the county.

Records

Clerk of court: deeds and platsfrom co.sanders.mt.us · checked 13 October 2026

Permits

Health department: septic and well
Public Health
from co.sanders.mt.us · checked 13 October 2026
Forms & Permitsfrom co.sanders.mt.us

Zoning and code

County Ordinances, Resolutions and Policiesfrom co.sanders.mt.us

County government

County government
The official website of Sanders County.
co.sanders.mt.us

See your own lot on these maps

Open Sanders County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Sanders County

When was Sanders County founded?: Sanders County was founded in 1906, formed from Missoula County, and named after Wilbur F. Sanders.
What is the county seat of Sanders County?: The county seat of Sanders County is Thompson Falls.
Is there an online parcel map for Sanders County?: Yes. A public source publishes a parcel map of 15,527 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Sanders County's boundary or name changed?: Sanders County was created in 1906 from Missoula County. Since then the Atlas of Historical County Boundaries records 3 later changes, chiefly involving Flathead County, Lincoln County and Missoula County.
Who issues building permits in Sanders County?: The county's page on building permits: Forms & Permits. Inside a city or town, ask that city first.
Who issues septic and well permits in Sanders County?: The county's page on septic systems and wells: Public Health.
Is my lot in a flood zone?: We do not have flood maps for Sanders County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby

Sanders CountyMontana