Welcome to Oregon Caves National Monument. We are about to go on a virtual Oregon Caves tour. Hope you’re ready to climb 527 stairs in the next half mile, mostly up. In order to protect this special place, I will ask you not to touch the cave walls as oils from your skin are left behind and the story of this cave is based on water. Oil and water just don’t mix.

The main entrance of four natural cave entrances
Elijah Davidson discovered the cave in 1874 on a hunting trip when he followed his dog chasing a bear into a dark cave opening. With only six matches he didn’t go far. Yet he ran out of fire and groped his way through the dark exiting the cave several hours later.

Entering Watson’s Grotto

Please watch your head. Is everybody comfortable? I can let you out the gate right now. Otherwise, you’re stuck with me until we reach the 110 exit, about half way through the Oregon Caves tour.

The rock surrounding us is marble which metamorphosed from limestone that was once at the bottom of the ocean. Uplift caused cracks and fractures in the marble which was then dissolved and eroded away by the power of water.

Leaving Watson’s Grotto

We’ll be walking through some of these enlarged fractures.

Petrified Gardens

And discover how water can also decorate a cave. As acidic water from above ground slowly works its way through cracks in the marble it absorbs and carries the mineral calcite. Then when the drop of water enters an air filled passage the carbon dioxide is released into the air, the water falls, and the calcite is deposited. If the water falls slowly the deposit is usually on the ceiling in the form of stalactites (that’s “c” for ceiling). If the water falls rapidly the calcite can be deposited as flowstone or stalagmites (that’s “g” for ground). We’ll see stalagmites further ahead.

At about 60 ft, deepest known Douglas Fir tree root

Enter the Belly of the Whale

An active creek still runs through parts of the cave and flows out the main entrance. This flowing water erodes rock and increases the size of passages. Openings in caves come and go over time changing the dynamics of the creek. This key-hole passage formed because of the change in flow. Evidence is seen by the shelf-like bevels on the walls. Look down into the River Styx to see how it still carves the marble.

Water erosion reveals the true shades-of-gray marble

Dynamite blasted connection tunnel

Yet humans also had a hand in shaping the cave. During the 1930s, the Civilian Conservation Corps blasted a connecting tunnel between two known cave passages to make touring easier. No more crawling on hands and knees unless desired.

Jack’s Pass once had a bottle-jack sporting some rock fall

We’ll just lip through Jack’s Pass into the Imagination Room.

I call this the “heart” of the cave, Imagination Room

This imaginative heart shape is formed by a combination of mineral and bacteria. Originally named Gnome’s Milk in Germany, it is believed to have curative properties similar to Neosporin.

We’re almost to the next natural cave entrance, or exit if you’re ready to leave. Just up these stairs…

Stairs from Imagination Room

….and through this squeeze.

Originally called “Fat man’s squeeze”

This is called the 110 exit as we have climbed about 110 feet up inside the mountain. Historically, it was referred to as “the ladies entrance” because of the easier and shorter journey deeper into the cave from here. Imagine crawling in long skirts. So you can leave here and walk a gentle quarter mile on paved trail back to the visitor center.

110 exit

Or continue with me deeper into the earth and discover more natural sculpture in part two of the tour.