When was Grays Harbor County founded?

Grays Harbor County was founded in 1854, formed from Lewis County and Thurston County, and named after Grays Harbor, Washington.

What is the county seat of Grays Harbor County?

The county seat of Grays Harbor County is Montesano.

Is there an online parcel map for Grays Harbor County?

Yes. A public source publishes a parcel map of 61,945 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Grays Harbor County's boundary or name changed?

Grays Harbor County was created in 1854 from Lewis County and Thurston County. Since then the Atlas of Historical County Boundaries records 15 later changes, chiefly involving Lewis County, Mason County and Pacific County. It was formerly called Chehalis.

Is my lot in a flood zone?

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

County · code 53027

Grays Harbor CountyWashington

Grays Harbor County is a Washington county formed in 1854 and named after Grays Harbor. Its county seat is Montesano.

Founded1854
County seatMontesano
Named forGrays Harbor, Washington
Land area1,901 sq mi + 322 sq mi water
Population75,636 2020 Census
Parcels mapped61,945 checked 15 October 2026

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

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1854 from Lewis County and Thurston County

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

Grays Harbor County was formed in 1854 from Lewis County and Thurston County, and named after Grays Harbor, Washington. Montesano is the county seat.

Deeds and plats from before 1854 for land now in Grays Harbor County may have been recorded in Lewis County and Thurston County.

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

1854
Grays Harbor County created Chehalis (now Grays Harbor) created by Washington Territory from Lewis and Thurston.
from Lewis from Thurston
14 April 1854 · Wash. Terr. Laws 1854, 1st sess., p. 472
1860
Lost territory Chehalis (now Grays Harbor) lost to Pacific.
to Pacific
13 January 1860 · Wash. Terr. Laws 1859, 7th sess., p. 429
1860
Gained territory Chehalis (now Grays Harbor) gained from Lewis, Sawamish (now Mason), and Thurston.
from Lewis from Sawamish from Masonfrom Thurston
25 January 1860 · Wash. Terr. Laws 1859, 7th sess., p. 444
1889
Became part of Washington Chehalis (now Grays Harbor) 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
1915
Renamed Chehalis renamed Grays Harbor.
formerly Chehalis
15 March 1915 · Wash. Laws 1915, 14th leg. sess., ch. 77/p. 250

Show all 16 changes (11 more)

1854
Grays Harbor County created Chehalis (now Grays Harbor) created by Washington Territory from Lewis and Thurston.
from Lewis from Thurston
14 April 1854 · Wash. Terr. Laws 1854, 1st sess., p. 472
1860
Lost territory Chehalis (now Grays Harbor) lost to Pacific.
to Pacific
13 January 1860 · Wash. Terr. Laws 1859, 7th sess., p. 429
1860
Gained territory Chehalis (now Grays Harbor) gained from Lewis, Sawamish (now Mason), and Thurston.
from Lewis from Sawamish from Masonfrom Thurston
25 January 1860 · Wash. Terr. Laws 1859, 7th sess., p. 444
1864
Gained territory Chehalis (now Grays Harbor) gained from Mason.
from Mason
30 January 1864 · Wash. Terr. Laws 1863-1864, 11th sess., p. 74
1867
Gained territory Chehalis (now Grays Harbor) gained from Jefferson, Lewis, Mason, and Wahkiakum, lost to Pacific.
from Jefferson from Lewis from Mason from Wahkiakum from Pacific
31 January 1867 · Wash. Terr. Laws 1866-1867, 14th sess., p. 49
1869
Lost territory Chehalis (now Grays Harbor) lost to Lewis and Wahkiakum.
to Lewis to Wahkiakum
2 December 1869 · Wash. Terr. Laws 1869, 2nd biennial sess., sec. 1/p. 296
1873
Lost territory Chehalis (now Grays Harbor) lost to Thurston.
to Thurston
10 November 1873 · Wash. Terr. Laws 1873, 4th biennial sess., pp. 482-483
1873
Lost territory Chehalis (now Grays Harbor) lost to Pacific.
to Pacific
14 November 1873 · Wash. Terr. Laws 1873, 4th biennial sess., p. 538
1877
Lost territory Chehalis (now Grays Harbor) lost to Mason.
to Mason
9 November 1877 · Wash. Terr. Laws 1877, 6th biennial sess., pp. 406-407
1879
Lost territory Chehalis (now Grays Harbor) lost to Pacific.
to Pacific
13 November 1879 · Wash. Terr. Laws 1879, 7th biennial sess., pp. 213-214
1888
Lost territory Chehalis (now Grays Harbor) lost to Lewis.
to Lewis
31 January 1888 · Wash. Terr. Laws 1887-1888, 11th biennial sess., p. 73
1889
Became part of Washington Chehalis (now Grays Harbor) 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
1905
Lost territory Chehalis (now Grays Harbor) lost to Jefferson when the Washington Superior Court of Thurston County ruled that the boundary between the two counties was to run along the township line between T. 23 N. and T. 24 N.
to Jefferson to Thurston
19 September 1905 · Wash. State Archives, "Jefferson County v Chehalis County" Superior Court records of the state of Wash. in and for Thurston County [1905]
1907
Changed Legislature authorized creation of Grays Harbor (proposed) from Chehalis (now Grays Harbor) and Jefferson. On 7 November 1907 the Washington State Supreme Court ruled this proposed creation of Grays Harbor unconstitutional and the change never took effect.
Jefferson
27 February 1907 · Abbott, 58-60; Wash. Laws 1907; 10th leg. sess., ch.47/pp. 62-69; "State of Washington v Superior Court for Pacific County" in Washington Rpts., 47:453-467
1915
Renamed Chehalis renamed Grays Harbor.
formerly Chehalis
15 March 1915 · Wash. Laws 1915, 14th leg. sess., ch. 77/p. 250
1925
Changed West boundary of Grays Harbor extended into the Pacific Ocean to intersect the west boundary of the State of Washington. 14 December 1925 · Wash. Laws 1925, 19th leg. extra sess., ch. 40/p. 29

Land and parcels

What the maps cover in Grays Harbor

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

Parcels Good enough

Lot lines and tax-map numbers for 61,945 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 Grays Harbor 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

Grays Harbor by the Census

Population

75,636 2020 Census count

Housing units

36,058 2020 Census count

Land area

1,901 square miles

Water area

322 square miles

People per sq mi

40 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.

Zoning and code

County Codefrom municode.com

County government

County government
The official website of Grays Harbor County.
co.grays-harbor.wa.us

See your own lot on these maps

Open Grays Harbor 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 Grays Harbor County

When was Grays Harbor County founded?: Grays Harbor County was founded in 1854, formed from Lewis County and Thurston County, and named after Grays Harbor, Washington.
What is the county seat of Grays Harbor County?: The county seat of Grays Harbor County is Montesano.
Is there an online parcel map for Grays Harbor County?: Yes. A public source publishes a parcel map of 61,945 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Grays Harbor County's boundary or name changed?: Grays Harbor County was created in 1854 from Lewis County and Thurston County. Since then the Atlas of Historical County Boundaries records 15 later changes, chiefly involving Lewis County, Mason County and Pacific County. It was formerly called Chehalis.
Is my lot in a flood zone?: We do not have flood maps for Grays Harbor County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby