When was Lewis County founded?

Lewis County was founded in 1845, formed from Vancouver District and Clark County, and named after Meriwether Lewis.

What is the county seat of Lewis County?

The county seat of Lewis County is Chehalis.

Is there an online parcel map for Lewis County?

Yes. A public source publishes a parcel map of 57,950 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Lewis County's boundary or name changed?

Lewis County was created in 1845 from Vancouver District and Clark County. Since then the Atlas of Historical County Boundaries records 19 later changes, chiefly involving Chehalis County, Grays Harbor County and Pacific County.

Is my lot in a flood zone?

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

County · code 53041

Lewis CountyWashington

Lewis County is a county in Washington with its county seat in Chehalis. It was created on December 21, 1845, by the Provisional Legislature of Oregon Territory from Vancouver District.

Founded1845
County seatChehalis
Named forMeriwether Lewis
Land area2,403 sq mi + 34 sq mi water
Population82,149 2020 Census
Parcels mapped57,950 checked 15 October 2026

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

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1845 from Vancouver District and Clark County

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

Lewis County was created in 1845 from Vancouver District (now Clark County) and was named after Meriwether Lewis. The county initially included the San Juan Islands, but lost them in 1846 when the Oregon Boundary Treaty with Great Britain established the international boundary at 49 degrees north latitude. Over the following decades, Lewis County underwent boundary adjustments, losing territory to the creation of Pacific, Thurston, Skamania, and Chehalis counties, while also gaining territory from Thurston and Pacific. In 1889, Lewis County continued as a Washington county when the state was admitted to the Union and Washington Territory was eliminated.

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

1845
Lewis County created Lewis created by the Provisional Legislature of Oregon Territory from Vancouver District (now Clark), included part of present Canada.
from Vancouver Districtfrom Clark
21 December 1845 · Ore. Terr. Laws, general and local, 1843-1849, p. 43
1846
Lost territory Lewis lost to British North America when the 1846 Oregon Boundary Treaty between the United States and Great Britain established the northern boundary of Oregon Territory at 49 degrees north latitude. Lewis included the San Juan Islands which were claimed by both the United States and Great Britain. 15 June 1846 · Hayes, 134, 171-174; Parry 100:40-42; Van Zandt, 18
1851
Lost territory Lewis lost to creation of Pacific.
to Pacific
3 February 1851 · Ore. Terr. Laws 1850, 2nd sess., p. 38
1853
Became part of Washington Lewis became a county in Washington Territory; eliminated from Oregon Territory. 2 March 1853 · Wash. Terr. Laws, 1854, 1st. sess., p. 32; Van Zandt, 155
1889
Became part of Washington Lewis continued as a Washington county when the state of Washington admitted to the Union and Washington Territory eliminated. 11 November 1889 · U.S. Stat., vol. 25, ch. 180[1889], p. 676; U.S. Stat. pres. proc., vol. 26[1889], p. 10; Van Zandt, 155-156

Show all 20 changes (15 more)

1845
Lewis County created Lewis created by the Provisional Legislature of Oregon Territory from Vancouver District (now Clark), included part of present Canada.
from Vancouver Districtfrom Clark
21 December 1845 · Ore. Terr. Laws, general and local, 1843-1849, p. 43
1846
Lost territory Lewis lost to British North America when the 1846 Oregon Boundary Treaty between the United States and Great Britain established the northern boundary of Oregon Territory at 49 degrees north latitude. Lewis included the San Juan Islands which were claimed by both the United States and Great Britain. 15 June 1846 · Hayes, 134, 171-174; Parry 100:40-42; Van Zandt, 18
1851
Lost territory Lewis lost to creation of Pacific.
to Pacific
3 February 1851 · Ore. Terr. Laws 1850, 2nd sess., p. 38
1852
Lost territory Lewis lost to creation of Thurston.
to Thurston
12 January 1852 · Ore. Terr. Laws 1851, 3rd reg. sess., p. 19
1852
Exchanged territory Lewis exchanged with Clark when eastern boundary of Lewis was redefined.
with Clark
17 January 1852 · Ore. Terr. Laws 1851, 3rd reg. sess., p. 30
1853
Gained territory Lewis gained from Thurston and exchanged with Clark.
from Thurston from Clark
1 February 1853 · Ore. Terr. Special Laws 1852, 4th reg. sess., p. 40
1853
Became part of Washington Lewis became a county in Washington Territory; eliminated from Oregon Territory. 2 March 1853 · Wash. Terr. Laws, 1854, 1st. sess., p. 32; Van Zandt, 155
1854
Lost territory Lewis lost to creation of Skamania and lost to Clarke.
to Skamaniato Clarke
9 March 1854 · Wash. Terr. Laws 1854, 1st sess., p. 473
1854
Gained territory Lewis gained from Pacific, lost to creation of Chehalis (now Grays Harbor).
from Pacific from Chehalisfrom Grays Harbor
14 April 1854 · Wash. Terr. Laws 1854, 1st sess., pp. 471-472
1854
Lost territory Lewis lost to creation of Cowlitz.
to Cowlitz
21 April 1854 · Wash. Terr. Laws 1854, 1st sess., p. 471
1855
Lost territory Lewis lost to Clarke when northern boundary of Clarke was redefined.
to Clarke
23 January 1855 · Wash. Terr. Laws 1854, 2nd sess., p. 39
1855
Lost territory Lewis lost to Cowlitz.
to Cowlitz
26 January 1855 · Wash. Terr. Laws 1854, 2nd sess., p. 36
1860
Lost territory Lewis lost to Chehalis (now Grays Harbor).
to Chehalisto Grays Harbor
25 January 1860 · Wash. Terr. Laws 1859, 7th sess., p. 444
1861
Gained territory Lewis gained from Pierce, exchanged with Thurston.
from Pierce from Thurston
26 January 1861 · Wash. Terr. Laws 1860, 8th sess., p. 33
1865
Lost territory Lewis lost to Pierce.
to Pierce
5 January 1865 · Wash. Terr. Laws 1864-1865, 12th sess., pp. 49-50
1867
Gained territory Lewis gained from Thurston, lost to Chehalis (now Grays Harbor), Pacific, and Wahkiakum.
from Thurston from Chehalis from Grays Harbor from Pacificfrom Wahkiakum
31 January 1867 · Wash. Terr. Laws 1866-1867, 14th sess., p. 48
1869
Gained territory Lewis gained from Chehalis (now Grays Harbor).
from Chehalisfrom Grays Harbor
2 December 1869 · Wash. Terr. Laws 1869, 2nd biennial sess., sec. 1/p. 295
1879
Gained territory Lewis gained from Skamania, Wahkiakum, and Yakima; lost to Pacific.
from Skamania from Wahkiakum from Yakima from Pacific
13 November 1879 · Wash. Terr. Laws 1879, 7th biennial sess., pp. 213-214
1888
Gained territory Lewis gained from Chehalis (now Grays Harbor).
from Chehalisfrom Grays Harbor
31 January 1888 · Wash. Terr. Laws 1887-1888, 11th biennial sess., p. 73
1889
Became part of Washington Lewis continued as a Washington county when the state of Washington admitted to the Union and Washington Territory eliminated. 11 November 1889 · U.S. Stat., vol. 25, ch. 180[1889], p. 676; U.S. Stat. pres. proc., vol. 26[1889], p. 10; Van Zandt, 155-156

Land and parcels

What the maps cover in Lewis

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

Parcels Good enough

Lot lines and tax-map numbers for 57,950 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 24 September 2026 · checked 15 October 2026
Address points Missing

No public address points layer found for Lewis County yet.
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

Lewis by the Census

Population

82,149 2020 Census count

Housing units

35,412 2020 Census count

Land area

2,403 square miles

Water area

34 square miles

People per sq mi

34 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

Lewis 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 Lewis County.
co.lewis.wa.us

See your own lot on these maps

Open Lewis 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.

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Questions

Common questions about Lewis County

When was Lewis County founded?: Lewis County was founded in 1845, formed from Vancouver District and Clark County, and named after Meriwether Lewis.
What is the county seat of Lewis County?: The county seat of Lewis County is Chehalis.
Is there an online parcel map for Lewis County?: Yes. A public source publishes a parcel map of 57,950 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Lewis County's boundary or name changed?: Lewis County was created in 1845 from Vancouver District and Clark County. Since then the Atlas of Historical County Boundaries records 19 later changes, chiefly involving Chehalis County, Grays Harbor County and Pacific County.
Is my lot in a flood zone?: We do not have flood maps for Lewis County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby