[3] Samuel Hill was an early promoter of the area, promoting better roads and building local landmarks such as a war memorial replica of Stonehenge (Maryhill Stonehenge) and a mansion that would become the Maryhill Museum of Art.

The Sam Hill Memorial Bridge across the Columbia River is named after him.

17.7% were of German, 14.0% United States or American, 11.1% English and 9.6% Irish ancestry.

23.80% of all households were made up of individuals, and 9.00% had someone living alone who was 65 years of age or older.

Klickitat is located in Washington's 4th congressional district, which has a Cook Partisan Voting Index of R+11 and has been represented by Republican Dan Newhouse since 2015.

In state government the county is part of the 14th district, represented by Gina Mosbrucker and Chris Corry in the Washington House of Representatives and Curtis King in the Washington State Senate.

[15] In presidential elections, Klickitat County has trended Republican in recent years.

[16] Richard Nixon (1960, 1972), Ronald Reagan,[17] Bill Clinton, and George W. Bush[18] all won the county twice.

In 2008 Democrat Barack Obama won Klickitat County over Republican John McCain by only 21 votes or percentage wise 48.85% to 48.64%.

In 2012 Republican candidate Mitt Romney won the county by a greater margin than in the previous election, with 51.74% of the vote compared to President Obama's 44.75%,[19] and Donald Trump doubled Romney's margin in 2016.