Jefferson County is a county located in the U.S. state of Washington. As of the 2020 census, the population was 32,977. The county seat and only incorporated city is Port Townsend. The county is named for Thomas Jefferson.
Jefferson County was formed out of Thurston County on December 22, 1852, by the legislature of Oregon Territory, and included the northern portion of the Olympic Peninsula. On April 26, 1854, the legislature of Washington Territory created Clallam County from the northwestern portion of this original area.
The Hood Canal Bridge connects Jefferson County to Kitsap County, Washington. The Coupeville-Port Townsend route of the Washington State Ferries connects the county to Whidbey Island in Island County, Washington.
Geography
According to the United States Census Bureau, the county has a total area of , of which is land and (17%) is water.
The county is split in three parts by its landforms: Eastern Jefferson County along the Strait of Juan de Fuca, Admiralty Inlet, Puget Sound, and the Hood Canal Central Jefferson County, which is uninhabited and lies in the Olympic Mountains within Olympic National Park and Olympic National Forest Western Jefferson County, along the Pacific Ocean.
Because of the mountainous barrier, there is no road lying entirely within Jefferson County that connects the eastern and western parts. The most direct land route between the two ends of the county involves a drive of approximately along U.S. Route 101 through neighbouring Clallam County. The mountains also block the damp Chinook winds, which make the climate much wetter in the west than the so-called eastern "banana belt" in the rain shadow.
Geographic features
Admiralty Inlet
Bolton Peninsula
Destruction Island
Discovery Bay
Hood Canal
Mount Olympus, the highest point on the Olympic Peninsula
Olympic Mountains
Olympic Peninsula
Pacific Ocean
Point Wilson
Port Townsend Bay
Protection Island
Puget Sound
Queets River
Quimper Peninsula
Strait of Juan de Fuca
Toandos (Coyle) Peninsula
Major highways
U.S. Route 101
State Route 20
State Route 104
Adjacent counties
Island County – northeast
Kitsap County – southeast
Mason County – south/southeast
Grays Harbor County – south/southwest
Clallam County – northwest
San Juan County – northeast
National protected areas
Olympic National Forest (part) Olympic National Park (part) Protection Island National Wildlife Refuge Quillayute Needles National Wildlife Refuge (part) Pacific Northwest National Scenic Trail (part)
Demographics
2010 census
As of the census of 2010, there were 29,872 people, 14,049 households, and 8,394 families living in the county. The population density was . There were 17,767 housing units at an average density of . The racial makeup of the county was 91.0% white, 2.3% American Indian, 1.6% Asian, 0.8% black or African American, 0.2% Pacific islander, 0.7% from other races, and 3.4% from two or more races. Those of Hispanic or Latino origin made up 2.8% of the population. In terms of ancestry, 20.8% were English, 20.3% were German, 13.9% were Irish, 8.3% were Norwegian, 5.9% were Scottish, and 4.2% were American.
Of the 14,049 households, 18.2% had children under the age of 18 living with them, 49.1% were married couples living together, 7.3% had a female householder with no husband present, 40.3% were non-families, and 32.2% of all households were made up of individuals. The average household size was 2.08 and the average family size was 2.57. The median age was 53.9 years.
The median income for a household in the county was $46,048 and the median income for a family was $59,964. Males had a median income of $45,616 versus $29,508 for females. The per capita income for the county was $28,528. About 8.9% of families and 13.5% of the population were below the poverty line, including 20.8% of those under age 18 and 7.4% of those age 65 or over.