When was Tillamook County founded?

Tillamook County was founded in 1853, formed from Clatsop County, Polk County and Yamhill County, and named after Tillamook.

What is the county seat of Tillamook County?

The county seat of Tillamook County is Tillamook.

Is there an online parcel map for Tillamook County?

Yes. A public source publishes a parcel map of 31,358 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Tillamook County's boundary or name changed?

Tillamook County was created in 1853 from Clatsop County, Polk County and Yamhill County. Since then the Atlas of Historical County Boundaries records 8 later changes, chiefly involving Clatsop County, Yamhill County and Lincoln County.

Is my lot in a flood zone?

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

County · code 41057

Tillamook CountyOregon

Tillamook County is in Oregon and was created on December 15, 1853, from parts of Clatsop, Polk, and Yamhill counties, with Tillamook as its seat.

Founded1853
County seatTillamook
Named forTillamook
Land area1,102 sq mi + 230 sq mi water
Population27,390 2020 Census
Parcels mapped31,358 checked 15 October 2026

Open the free map Click any parcel in Tillamook County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1853 from Clatsop County, Polk County and Yamhill County

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

Originally created from Clatsop, Polk, and Yamhill counties in 1853, Tillamook County was not fully organized at first and was attached to Yamhill for judicial purposes. The county became an Oregon county when the state was admitted to the Union on February 14, 1859, and Oregon Territory was eliminated. Over the following decades, Tillamook's boundaries changed through multiple land exchanges and transfers with neighboring counties including Clatsop, Yamhill, Polk, Washington, and Lincoln.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries; the 5 that matter most are shown first.

1853
Tillamook County created Tillamook created by Oregon Territory from Clatsop, Polk, and Yamhill; Tillamook not fully organized, attached to Yamhill "for judicial purposes."
from Clatsop from Polk from Yamhill
15 December 1853 · Ore. Terr. Special Laws, 1853, 5th reg. sess., p. 6; Ore. Terr. Rev. Stat. 1853, p. 63
1855
Lost territory Tillamook lost to Clatsop.
to Clatsop
15 January 1855 · Ore. Terr. Special Laws 1854, 6th reg. sess., p. 33
1859
Became part of Oregon Tillamook became an Oregon county when the state of Oregon was admitted to the Union and Oregon Territory was eliminated. 14 February 1859 · U.S. Stat., vol. 11, ch. 33[1859], secs. 1-2/pp. 383-384 Ore. Laws 1860, 1st reg. sess., pp. 28-30
1870
Gained territory Tillamook gained from Clatsop; attached to Yamhill "for judicial purposes."
from Clatsop from Yamhill
22 October 1870 · Ore. Laws 1870, 6th reg. sess., pp. 24-25
1887
Exchanged territory Tillamook exchanged with Yamhill.
with Yamhill
15 February 1887 · Ore. Laws 1887, gen., 14th reg. sess., p. 147

Show all 10 changes (5 more)

1853
Tillamook County created Tillamook created by Oregon Territory from Clatsop, Polk, and Yamhill; Tillamook not fully organized, attached to Yamhill "for judicial purposes."
from Clatsop from Polk from Yamhill
15 December 1853 · Ore. Terr. Special Laws, 1853, 5th reg. sess., p. 6; Ore. Terr. Rev. Stat. 1853, p. 63
1855
Lost territory Tillamook lost to Clatsop.
to Clatsop
15 January 1855 · Ore. Terr. Special Laws 1854, 6th reg. sess., p. 33
1859
Became part of Oregon Tillamook became an Oregon county when the state of Oregon was admitted to the Union and Oregon Territory was eliminated. 14 February 1859 · U.S. Stat., vol. 11, ch. 33[1859], secs. 1-2/pp. 383-384 Ore. Laws 1860, 1st reg. sess., pp. 28-30
1870
Gained territory Tillamook gained from Clatsop; attached to Yamhill "for judicial purposes."
from Clatsop from Yamhill
22 October 1870 · Ore. Laws 1870, 6th reg. sess., pp. 24-25
1887
Exchanged territory Tillamook exchanged with Yamhill.
with Yamhill
15 February 1887 · Ore. Laws 1887, gen., 14th reg. sess., p. 147
1891
Gained territory Tillamook gained from Clatsop.
from Clatsop
20 February 1891 · Ore. Laws 1891, gen., 16th reg. sess., pp. 102-103
1891
Exchanged territory Tillamook exchanged with Polk.
with Polk
21 February 1891 · Ore. Laws 1891, gen., 16th reg. sess., pp. 139-140
1893
Lost territory Tillamook lost to creation of Lincoln, and lost to Clatsop.
to Lincoln to Clatsop
20 February 1893 · Ore. Laws 1893, gen., 17th reg. sess., pp. 68-78
1893
Exchanged territory Tillamook exchanged with Washington.
with Washington
22 February 1893 · Ore. Laws 1893, gen., 17th reg. sess., pp. 161-162
1981
Boundary clarified Tillamook redefined to amend description in Oregon Revised Statutes (no change).
no change
13 July 1981 · Ore. Laws 1981, 61st reg. sess., ch. 332/pp. 355-356

Land and parcels

What the maps cover in Tillamook

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

Parcels Good enough

Lot lines and tax-map numbers for 31,358 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 1 October 2026 · checked 15 October 2026
Address points Official

One point per address, 21,654 in all from State of Oregon — Department of Administrative Services Geospatial Enterprise Office (GEOHub) with Oregon Department of Emergency Management 9-1-1 program.
edited 16 January 2026 · checked 13 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

Tillamook by the Census

Population

27,390 2020 Census count

Housing units

18,919 2020 Census count

Land area

1,102 square miles

Water area

230 square miles

People per sq mi

25 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

Tillamook County's official site

We have found the county's site but not its offices yet; start there.

County government

County government
The official website of Tillamook County.
co.tillamook.or.us

See your own lot on these maps

Open Tillamook 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 Tillamook County

When was Tillamook County founded?: Tillamook County was founded in 1853, formed from Clatsop County, Polk County and Yamhill County, and named after Tillamook.
What is the county seat of Tillamook County?: The county seat of Tillamook County is Tillamook.
Is there an online parcel map for Tillamook County?: Yes. A public source publishes a parcel map of 31,358 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Tillamook County's boundary or name changed?: Tillamook County was created in 1853 from Clatsop County, Polk County and Yamhill County. Since then the Atlas of Historical County Boundaries records 8 later changes, chiefly involving Clatsop County, Yamhill County and Lincoln County.
Is my lot in a flood zone?: We do not have flood maps for Tillamook County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby