Clark County was the first county of Washington, named after William Clark of the Lewis and Clark Expedition. It was created by the provisional government of Oregon Territory on August 20, 1845, and at that time covered the entire present-day state.
On August 13 1848, President James K. Polk signed an act creating the entire region as the Oregon Territory. On September 3 1849, the Oregon Territorial Legislature modified the borders again and changed its name to Clarke County in honor of explorer William Clark. At this time it included all of present day Washington and continued to be divided and subdivided until reaching its present area in 1880. It was not until 1925 that the spelling was corrected to its present form.
In September 1902 the Yacolt Burn, the largest fire in state history, began in neighboring Skamania County and swept west along a 12 mile front to Yacolt, nearly engulfing the town. Salvaging the remaining timber was a lucrative industry for a time.
Unlike the Seattle suburbs, Portland's suburbs often lean conservative. Battle Ground was the only western Washington suburb to give George W. Bush more than 60 percent of the vote in 2004, besides the extremely affluent Seattle suburb of Hunts Point. Most of northern Clark County also voted heavily for Bush, offsetting some significant victories for John Kerry in Vancouver and the unincorporated communities around it.
Clark County's location in the Portland media market often results in the county voting differently on initiatives than the rest of the state. In addition, unlike the fairly socially liberal Seattle suburbs, Clark County is apt to vote for some types of socially conservative legislation (such as against legalising marijuana), which is seen as not appealing to family voters in the area.
Clark County is surrounded on two sides by the Columbia River and on the north by the North Fork of the Lewis River. The East Fork of the Lewis River and the Washougal River cut across the county. The largest stream arising solely within the county is Salmon Creek, which terminates at Vancouver Lake before eventually flowing into the Columbia River.
Like most of Oregon and Washington south of Puget Sound into the Willamette Valley the landscape and climate of Clark County are determined by its placement between the volcanic Pacific Coast and Cascade Ranges, where glaciation helped form a U-shaped valley which meets the river valley of the Columbia River as it leaves the Columbia River Gorge. Volcanic andisol soils are common, with fertile mollisols in the lower areas. The central and southwest areas of the county are generally flat floodplains, sculpted by torrents of prehistoric Lake Missoula. A series of dramatic floods known as the Missoula Floods took place 15,000 - 13,000 years ago, as several ice dams melted, forming a series of low steps such as the "Heights", "Mill Plain", "Fourth Plain" and "Fifth Plain". Clark County's Köppen climate classification is "Csa."
Many lakes border the river in the lowlands near Ridgefield, including Vancouver Lake. Eastern and northern Clark County contain forested foothills of the Cascade Mountains, rising to an elevation of 4,000 feet on the border with Skamania County. Larch Mountain is the county's highest free-standing peak.
Flora and fauna of the region include the normal ecological succession from lowland big leaf maple and western red cedar through Garry oak on up through fire-dependent species such as lodgepole pine and Douglas fir, as well as grand fir, silver fir and other species common to Gifford Pinchot National Forest. In addition to a wide variety of birds including great blue heron, raptors such as barred owl, osprey, red-tailed hawk and bald eagle, corvids (raven, crow, scrub and Steller's jay) and others, the native streams are home to various species of salmon and the Vancouver Trout Hatchery. Larger mammals include black-tailed deer, coyote, raccoon, skunk and invasive opossum. Common foods used by the indigenous people such as the Klickitat tribe and Chinook included salmon, huckleberry and Camassia quamash (after which the city of Camas, Washington is named).
Mount Hood, Mount Saint Helens and Mount Adams are all visible from Clark County, and cold winter winds through the Columbia River Gorge often bring freezing rain and a coating of glaze ice or clear ice known locally as a "silver thaw," especially in southeastern areas of the county closest to the gorge. The counterpart to this are warm winds from the southeast known locally as the "Pineapple Express."
Spring thaws can often swell county waterways, with two of the more destructive floods being those of the Columbia River in June 1894 and May, 1948. The 1948 Memorial Day flood almost topped the Interstate Bridge's support piers and completely destroyed nearby Vanport, Oregon. Construction of the The Dalles Dam and destruction of Celilo Falls are credited with a decrease in such floods.
Significant windstorms in Clark County include the Columbus Day windstorm of October 12, 1962, and an April 6, 1972 tornado which rated F3 on the Fujita scale, striking a local school. A "Friday the 13th" storm in November of 1981 brought winds up to 70 miles per hour, with other storms including the inauguration day storm of January 20, 1993, the Guadalupe Day storm of December 12th, 1995 (with winds up to 95 miles per hour at Washougal, Washington) and small tornado on January 10, 2008, which destroyed a boathouse at Vancouver Lake and caused damage to buildings in Hazel Dell before dissolving near Hockinson.
In addition to helping shape county policy, the Youth Commission takes on a youth-driven project each year to promote or combat an issue. Past youth-driven projects include a Civil Rights Open House at the Youth House, a benefit concert for Invisible Children, and Freedom's Answer. Each year, the Youth Commission also hosts a Clark County Youth Achievement Celebration at Skyview High School to honor youth around the county.
In 2008, the CCYC plans to be involved in shaping Sustainability Policy.
There were 127,208 households out of which 37.20% had children under the age of 18 living with them, 56.80% were married couples living together, 10.30% had a female householder with no husband present, and 28.50% were non-families. 21.80% of all households were made up of individuals and 6.80% had someone living alone who was 65 years of age or older. The average household size was 2.69 and the average family size was 3.15.
In the county, the population was spread out with 28.70% under the age of 18, 8.40% from 18 to 24, 30.80% from 25 to 44, 22.60% from 45 to 64, and 9.50% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 98.50 males. For every 100 females age 18 and over, there were 95.90 males.
The median income for a household in the county was $48,376, and the median income for a family was $54,016. Males had a median income of $41,337 versus $28,537 for females. The per capita income for the county was $21,448. About 6.90% of families and 9.10% of the population were below the poverty line, including 11.70% of those under age 18 and 6.80% of those age 65 or over.