Crooked River caldera

{{Short description|Volcano in Oregon, USA}}

{{Infobox mountain

| name = Crooked River caldera

| photo =

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| map = Oregon

| map_caption = none

| location = Deschutes, Crook, and Jefferson counties, Oregon, U.S.

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| coordinates = {{coord|44.3|N|120.9|W|type:mountain_region:US-OR_scale:100000|format=dms|display=inline,title}}

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| topo =

| type = Caldera, supervolcano

| age = 29.5 Ma

| volcanic_arc = Cascade Volcanic Arc, Ochoco Mountains

| last_eruption = 29.5 million years ago

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The Crooked River caldera is a large and ancient volcano that straddles three central Oregon counties. The diameter of the caldera is about {{convert|41|x|27|km}} and is notable for the welded tuff present at Gray Butte, Smith Rock, Powell Buttes, Grizzly Mountain and Barnes Butte. The volcano is considered extinct and last erupted about 29.5 Ma. The Crooked River Caldera is also a supervolcano.

{{cite web

| url = http://www.oregongeology.org/pubs/og/OGv69n01.pdf

| title = Field trip guide to the Oligocene Crooked River caldera: Central Oregon's Supervolcano, Crook, Deschutes, and Jefferson Counties, Oregon

| work = Oregon Geology

| publisher = Oregon Department of Geology and Mineral Studies

| date = 2009

| accessdate = 2014-12-29}}