Mount Tabor is a dormant cinder cone of the Boring Lava Field, an extensive network of cinder cones and small shield volcanoes ranging from Boring, Oregon, to southwest Washington, and dating to the Plio-Pleistocene era. The lava field has been extinct for over 300,000 years. Three other cinder cones from this field also lie within the city of Portland: Rocky Butte, Powell Butte, and Kelly Butte.
Portland is one of four cities in the United States to have an extinct volcano within its boundaries. Bend is the only other city in Oregon with a volcano within its city limits (Pilot Butte). The two remaining urban volcanos are Jackson Volcano in Jackson, Mississippi, and Diamond Head in Honolulu.
The volcanic nature of Mount Tabor became known in 1912, years after reservoirs and a public park were developed on it. The name refers to Mount Tabor, Israel, part of Portland's distinct Jewish culture and past. It was named by Plympton Kelly, son of Oregon City pioneer resident Clinton Kelly.
Several articles have been published on the volcanic nature of Mt. Tabor Park. Please visit Willamette Week Q & A, Geoprisms, and Columbia River Images for more details, or download our brochure on the Geological History of Mt. Tabor Park. This 1975 report compiled by the Oregon Dept. of Geology and Mineral Industries is an excellent resource.