BEACON ROCK — (you can view Beacon Rock at Vista House or on I-84 across the river just west of Bonneville dam)

Beacon Rock is a 848’ high remnant core of an ancient volcano. The ice-age floods through the Gorge eroded the softer material away, leaving this unique geological structure standing by itself on the banks of the Columbia River.  It is composed of basaltic andesite, and has been eroding for thousands of years.  "Beacon Rock" was originally named by Lewis and Clark on their expedition to the Pacific Ocean on October 31, 1805. It was near Beacon Rock that they first measured tidal influences from the ocean on the Columbia River. In 1811, Alexander Ross of the John Jacob Astor expedition called the rock "Inoshoack Castle." The rock was known as "Castle Rock" until, in 1916, the United States Board of Geographic Names restored the name "Beacon Rock.".  No record exists of an ascent up the rock prior to 1901.  Henry J. Biddle purchased the rock in order to build a trail to the top, and was completed in 1918 after working on it for 2 years. It is the largest freestanding monolith in the US, and the 2^nd largest in the world, after Gibraltar.