[2] The county seat and largest incorporated city is Stevenson,[3] although the Carson River Valley CDP is more populous.

Skamania County is included in the Portland-Vancouver-Hillsboro, OR-WA Metropolitan Statistical Area.

The county was founded in 1854 and derives its name from the Cascades Chinook word sk'mániak, meaning 'swift waters'.

[4] The area delineated by the future Washington state boundary began to be colonized at the start of the nineteenth century, both by Americans and British subjects.

The condominium was unwieldy and led to continual argument, and occasional conflict.

The status of the Washington area was settled in 1846, when the Oregon Treaty ceded the land south of North latitude 49 degrees to American control.

[6] After that, Skamania County retained its shape, including through the period after Washington became the 42nd state of the Union in 1889.

The ordinance forbids the slaying of any "nocturnal primate mammal variously described as an ape-like creature or a sub-species of Homo sapiens ... generally and commonly known as a 'Sasquatch', 'Yeti', 'Bigfoot', or 'Giant Hairy ape'", subject to a maximum penalty of a $10,000 fine and five years imprisonment.

Although its passage coincided with April Fool's Day, Ordinance 69-01 was real, was amended in 1984, and has not been repealed.

Its purposes included protection of residents and visitors from in the county from a very real concern, "an influx of scientific investigators as well as casual hunters, many armed with lethal weapons", who had been attracted to the area by reported sightings of a creature.

[20] In terms of ancestry, 20.6% were German, 15.7% were Irish, 11.0% were English, 6.3% were Norwegian, and 5.0% were American.

17.7% were of German, 12.5% English, 12.1% Irish, 11.2% United States or American and 5.2% Norwegian ancestry.

In the year 2000 there were more Seventh-day Adventists in Skamania County than adherents of any other religious group.