Mount Multnomah is an invalidated hypothetical ancient volcano postulated in a 1925 publication by geologist Edwin T. Hodge. It was proposed to exist in central Oregon at the present day location of the Three Sisters region. It was estimated to have been around 16,000-foot (4,900 m) tall, and was believed destroyed in a fashion similar to Mount Mazama's eruption resulting in what is now Crater Lake in southern Oregon.

Cascade Range, Cascades, Chaîne des, Geology, Geology Oregon, Geology Oregon Lane County, Géologie Oregon, Géologie Oregon Lane, Montagnes Oregon Lane, Mountains, Mountains Oregon Lane County, North America Cascade Range, Oregon, Oregon Lane County, Oregon Three Sisters, Oregon authors, Three Sisters (Or.), Three Sisters, Or. (Mountains), Volcan

The Cascade Plateau History of the Cascade Plateau History of Mount Multnomah summarized Climate Flora and fauna of the Tree Sisters Accessibility

"August 1, 1925.""First Edition 5000 Copies."

"August 1, 1925.""First Edition 5000 Copies."