Kitsap County is a county in the U.S. state of Washington. As of the 2020 census, its population was 275,611. Its county seat is Port Orchard; its largest city is Bremerton. The county, formed out of King County and Jefferson County on January 16, 1857, is named for Chief Kitsap of the Suquamish Tribe. Originally named Slaughter County, it was soon renamed.

Kitsap County comprises the Bremerton–Silverdale–Port Orchard, WA Metropolitan Statistical Area, which is also included in the Seattle–Tacoma, WA Combined Statistical Area.

The United States Navy is the largest employer in the county, with installations at Puget Sound Naval Shipyard, Naval Undersea Warfare Center Keyport, and Naval Base Kitsap (which comprises former NSB Bangor and NS Bremerton).

Kitsap County is connected to the eastern shore of Puget Sound by Washington State Ferries routes, including the Seattle-Bremerton Ferry, Southworth to West Seattle via Vashon Island, Bainbridge Island to Downtown Seattle, and from Kingston to Edmonds, Washington. Kitsap Transit provides passenger-only fast ferry service between Bremerton and Seattle, Kingston and Seattle, and Southworth and Seattle.

History

The Kitsap Peninsula was originally acquired by the U.S. Government in three pieces by three treaties negotiated with the Native American tribes:

  • The Treaty of Medicine Creek, signed December 26, 1854, ratified March 3, 1855
  • The Treaty of Point Elliott, signed January 22, 1855, ratified April 11, 1859
  • Point No Point Treaty, signed January 26, 1855, ratified March 8, 1859.

Territorial Governor Isaac Stevens represented the United States in all three negotiations.

When the Washington Territory was organized in 1853, the Kitsap Peninsula was divided between King County to the east and Jefferson County to the west. Official public papers were required to be filed at the county seat, which meant Peninsula business people had to travel to either Seattle or Port Townsend to transact business. On the understanding that they would "bring home a new county," area mill operators George Meigs and William Renton supported the candidacies to the Territorial Legislature of two employees from their respective mills: Timothy Duane Hinckley from Meigs' and S.B. Wilson from Renton's.

Upon arrival in Olympia, the two men introduced bills to create a new county, to be named "Madison". Representative Abernathy from Wahkiakum County proposed an amendment to name it "Slaughter", in recognition of Lt. William Alloway Slaughter, who had been killed in 1855 in the Yakima War. The bill passed as amended. It was signed by Governor Isaac Stevens on January 16, 1857. The county seat would be located in Meigs's mill town at Port Madison.

In Slaughter County's first election on July 13, 1857, voters were given the opportunity to rename the county. The options were "Mill", "Madison" or "Kitsap". Slaughter was not one of the options. Kitsap won by an overwhelming majority.

Kitsap County is home to several major United States Navy facilities, collectively named Naval Base Kitsap, and grew in response to wars and conflicts in the 20th century. Bremerton, the site of the Puget Sound Naval Shipyard, peaked at 80,000 residents during World War II. Naval Submarine Base Bangor was developed in the 1980s to store nuclear weapons for submarines and contributed to the county's population growth during the decade from 147,000 to 190,000.

Geography

According to the United States Census Bureau, the county has a total area of , of which is land and (30%) is water. It is the fourth-smallest county in Washington by land area and third-smallest by total area.

In addition to occupying most of the Kitsap Peninsula, the county includes both Bainbridge Island and Blake Island. Kitsap County has approximately of shoreline.

The portion of the county north of Silverdale is often referred to as North Kitsap, and the portion south of Bremerton as South Kitsap.

Geographic features

  • Bainbridge Island
  • Blake Island
  • Buck Lake
  • Colvos Passage
  • Dyes Inlet
  • Hood Canal
  • Kitsap Peninsula
  • Liberty Bay
  • Port Gamble
  • Port Madison
  • Port Orchard
  • Puget Sound
  • Sinclair Inlet
  • Blue Hills
  • Seattle Fault Zone
  • Kitsap Lake
  • Ostrich Bay
  • Horseshoe Lake

Adjacent counties

  • Island County - northeast
  • Snohomish County - east
  • King County - east/southeast
  • Pierce County - south/southeast
  • Mason County - southwest
  • Jefferson County - northwest

Notable parks

  • Blake Island Marine State Park,
  • Bloedel Reserve
  • Camp Yeomalt
  • Eagledale Park
  • Fay Bainbridge Park
  • Fort Ward Park
  • Illahee State Park
  • Kitsap Memorial State Park
  • Manchester State Park
  • Port Gamble Forest Heritage Park,
  • Pritchard Park
  • Scenic Beach State Park

Economy

The largest employer in Kitsap County is Naval Base Kitsap, which had a total of 38,187 workers in 2024; approximately 63percent are civilian employees, while the rest are military personnel. Other major employers include St. Michael Medical Center in Silverdale, local school districts, the county government, and Olympic College.

Demographics