• Speleothems in Miller's Chapel.

    Oregon Caves

    National Monument Oregon

Environmental Factors

The cave at Oregon Caves National Monument is a solution cave formed in a marble outcrop located in Siskiyou mountain range of Southwest Oregon.

The marble formed as a consequence of tectonic activity. Limestone of the Juan de Fuca oceanic plate subducted under the North American continental plate and was metamorphosed (recrystallized) into marble. The intense faulting and folding incurred by the marble resulted in a geosynclinic karst system. The predominant rectilinear branchwork passages are a result of the steep upper profile of the bedding planes.

The surrounding forest, watershed, and temperature can influence the cave. To learn how read more!

Did You Know?

From the vista on the Cliff Nature trail you can see the nation's largest serpentine rock outcrops in the distance.

The mountains surrounding Oregon Caves are composed of ocean crust including rocks uplifted directly from the mantle. These mantle rocks make up one of the largest serpentine rock outcrops in the nation.