Between 20,000 and 110,000 years ago, a period of volcanism
resulted in a flow of lava which met an obstacle in what is now the
valley of the Cowlitz River's Clear Fork. Although the nature of
the obstruction is not known, the volcanic extrusion of dacite
formed a deep pool and congealed under particular conditions,
allowing the lava to 'crystallize' into basaltic columns.
Subsequent erosion by wind and water have left the formations
exposed to view here at the Palisades.
Originally, I had thought to submit this as an Earthcache, but
my love of the hunt and trinkets persuaded me that others might
feel the same. Please take a few minutes to admire the geology
before searching for the hidden container nearby (small
decon.).