When was Kitsap County founded?

Kitsap County was founded in 1857, formed from King County, and named after Chief Kitsap.

What is the county seat of Kitsap County?

The county seat of Kitsap County is Port Orchard.

Is there an online parcel map for Kitsap County?

Yes. A public source publishes a parcel map of 139,605 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Kitsap County's boundary or name changed?

Kitsap County was created in 1857 from King County. Since then the Atlas of Historical County Boundaries records 8 later changes, chiefly involving Mason County, Pierce County and Sawamish County. It was formerly called Slaughter.

Who issues building permits in Kitsap County?

The county's page on building permits: Permit Services. Inside a city or town, ask that city first.

Is my lot in a flood zone?

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

County · code 53035

Kitsap CountyWashington

Kitsap County is a Washington county established in 1857 with its seat in Port Orchard. The county was named after Chief Kitsap.

Founded1857
County seatPort Orchard
Named forChief Kitsap
Land area395 sq mi + 171 sq mi water
Population275,611 2020 Census
Parcels mapped139,605 checked 15 October 2026

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

Updated 20 October 2026

Census outline · seat marked

History

Formed in 1857 from King County

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

Kitsap County was formed in 1857 from King County, and named after Chief Kitsap. Port Orchard is the county seat.

Deeds and plats from before 1857 for land now in Kitsap County may have been recorded in King County.

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

1857
Kitsap County created Slaughter (now Kitsap) created by Washington Territory from King.
from King
16 January 1857 · Wash. Terr. Laws 1856, 4th sess., p. 52
1857
Renamed Slaughter renamed Kitsap as the result of a vote in the annual election held 17 July 1857.
formerly Slaughter
17 July 1857 · David Peterson, Kitsap County Clerk, email correspondence of 27 January 2005
1858
Lost territory Kitsap implicitly lost to Sawamish (now Mason) when the south line of Kitsap was redefined.
to Sawamishto Mason
13 January 1858 · Wash. Terr. Laws 1857, 5th sess., pp. 51-52
1859
Lost territory Kitsap lost to Pierce.
to Pierce
29 January 1859 · Wash. Terr. Laws 1858, 6th sess., p. 59
1889
Became part of Washington Kitsap 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 9 changes (4 more)

1857
Kitsap County created Slaughter (now Kitsap) created by Washington Territory from King.
from King
16 January 1857 · Wash. Terr. Laws 1856, 4th sess., p. 52
1857
Renamed Slaughter renamed Kitsap as the result of a vote in the annual election held 17 July 1857.
formerly Slaughter
17 July 1857 · David Peterson, Kitsap County Clerk, email correspondence of 27 January 2005
1858
Lost territory Kitsap implicitly lost to Sawamish (now Mason) when the south line of Kitsap was redefined.
to Sawamishto Mason
13 January 1858 · Wash. Terr. Laws 1857, 5th sess., pp. 51-52
1859
Lost territory Kitsap lost to Pierce.
to Pierce
29 January 1859 · Wash. Terr. Laws 1858, 6th sess., p. 59
1861
Lost territory Kitsap lost to Sawamish (now Mason).
to Sawamishto Mason
30 January 1861 · Wash. Terr. Laws 1860, 8th sess., p. 56
1867
Gained territory Kitsap gained from Mason and Pierce.
from Mason from Pierce
31 January 1867 · Wash. Terr. Laws 1866-1867, 14th sess., p. 46
1869
Lost territory Kitsap lost to Mason.
to Mason
2 December 1869 · Wash. Terr. Laws 1869, 2nd biennial sess., sec. 1/p. 293
1877
Lost territory Kitsap lost to Mason.
to Mason
9 November 1877 · Wash. Terr. Laws 1877, 6th biennial sess., pp. 406-407
1889
Became part of Washington Kitsap 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 Kitsap

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

Parcels Good enough

Lot lines and tax-map numbers for 139,605 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 Kitsap 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

Kitsap by the Census

Population

275,611 2020 Census count

Housing units

113,248 2020 Census count

Land area

395 square miles

Water area

171 square miles · 30% of the county, including large bodies of water

People per sq mi

698 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

Assessor and property recordsfrom kitsap.gov · checked 13 October 2026

Permits

Permit Servicesfrom kitsap.gov
Administrative Permit Decisionsfrom kitsap.gov

Zoning and code

Planning and zoning
19-03608
from kitsap.gov · checked 13 October 2026
Critical Areas Ordinancefrom kitsap.gov
Quick Zoning Guidefrom kitsap.gov

County government

County government
The official website of Kitsap County.
kitsap.gov

See your own lot on these maps

Open Kitsap 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 Kitsap County

When was Kitsap County founded?: Kitsap County was founded in 1857, formed from King County, and named after Chief Kitsap.
What is the county seat of Kitsap County?: The county seat of Kitsap County is Port Orchard.
Is there an online parcel map for Kitsap County?: Yes. A public source publishes a parcel map of 139,605 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Kitsap County's boundary or name changed?: Kitsap County was created in 1857 from King County. Since then the Atlas of Historical County Boundaries records 8 later changes, chiefly involving Mason County, Pierce County and Sawamish County. It was formerly called Slaughter.
Who issues building permits in Kitsap County?: The county's page on building permits: Permit Services. Inside a city or town, ask that city first.
Is my lot in a flood zone?: We do not have flood maps for Kitsap County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby