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Department of Geology and Mineral Industries

Learn More About Oregon's Geology
An interesting fact about Oregon is that while the western half experiences heavy rainfall each year, the eastern half is high-desert country. The chain of magnificent towering volcanic peaks that makes up the Cascade Range separates the state into these two extremes. Another fact; before the Cascades first formed (there are actually two different sets), Oregon was a tropical paradise! Go exploring and learn more about Oregon´s geology!

 
 
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Coastal Range Klamath Mountains Deschutes-Columbia Plateau Blue Mountains High Lava Plains Cascade Range Willamette Valley Basin & Range & Owyhee uplands Basin & Range & Owyhee uplands
 
Graphic by Elizabeth L. Orr, Geology of Oregon,
available from Nature of the Northwest