Inside the Cave
At least eight of the fifteen bat species found in Oregon occur within the boundaries of Oregon Caves National Monument. Most bats seen by the main trail are Townsend big-eared bats, Yuma bats, long-eared myotis bats, silvered-haired bat, big brown bat, Western small-footed bat, California myotis, little brown myotis, and fringed myotis.
Outside the Cave
Squirrels, chipmunks, and fox are quite common. Black bears, cougars, and Mountain beaver are a bit more secretive.
Did You Know?
Carbon dioxide mixes with water that condenses on the wall of the cave to create a very weak acid. Over long periods of time this "acid dew" eats away at the marble walls of Oregon Caves making the cave larger.