Part of the Tatoosh Range.
The Tatoosh Range was a granitic pluton that slowly cooled and was eroded into its current shape. Part of the roof of the pluton is still there on the top of Unicorn Peak. 

Part of the Tatoosh Range.

The Tatoosh Range was a granitic pluton that slowly cooled and was eroded into its current shape. Part of the roof of the pluton is still there on the top of Unicorn Peak.