Rocky Butte is an extinct volcanic butte in northeast Portland that rises 613 feet and forms part of the Boring Lava Field. Erupting roughly 285,000 to 500,000 years ago, it is the eroded core of a late Pleistocene volcano with two vents, composed mainly of calc-alkaline basaltic andesite. The Missoula Floods reshaped the hill, heavily eroding one side while its tougher volcanic plug helped it survive when other nearby features were buried or destroyed. Beyond its geology, the butte has housed several institutions, retains a rotating airway beacon and Works Progress Administration features, and now serves as parkland and a popular local overlook.

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Portland, Oregon · USA