Oregon Caves National Monument

Oregon Caves may surprise you. Small in size, it is rich in diversity. That richness can be found both underground amidst narrow, winding passageways and above ground where old growth forest harbors a fantastic array of animals and plants found nowhere else. You will discover a land rich in conifers, wildflowers, birds, and amphibians. An active marble cave and underground stream reveal the inside of one of the world’s most diverse geologic realms.

A Dog and a Bear Went into a Cave

As his last match flickered out, 24-year-old hunter Elijah Davidson found himself in the total blackness of the cave. Davidson was chasing after his dog Bruno, who in turn was pursuing a bear. One following the other, the dog and bear entered a dark hole on the mountainside. Davidson stopped at the mysterious dark entrance. He could see nothing, but an agonizing howl pulled him into the cave to save his dog. Now the matches were gone and Davidson was in total darkness. Fortunately, he was able to wade down a gurgling, ice-cold stream and find his way back into daylight. Bruno soon followed. It was 1874.

Joaquin Miller

Later, other brave souls explored deeper into the cave, returning home to tell of its great beauty and mystery. In 1907, a party of influential men, including Joaquin Miller, the "poet of the Sierras," visited the cave. Charmed by it, Miller wrote of the "Marble Halls of Oregon." The ensuing publicity alerted federal officials to the possibility of preserving the cave. In 1909 President William Howard Taft proclaimed a tract of 480 acres as Oregon Caves National Monument. In 1922 an automobile road reached the park, and 12 years later a six-story hotel, the Chateau, was constructed. The very same year, 1934, Oregon Caves National Monument was transferred from the Forest Service to the National Park Service, which still administers it.

Workers blasted tunnels and widened passages in the cave during the 1930s. They put waste rocks in side passages, covering many limestone formations. Changes in air flow patterns altered the growth of formations and caused greater swings in temperature. Freezing water now cracked rock layers. Lights in the cave promoted the growth of algae, which turned portions of the cave green and dissolved some formations. Smoke from torches and lint coming off visitors’ clothing blackened other portions.

Cave Restoration

Since 1985 the National Park Serve has removed more than a thousand tons of rubble in its effort to restore the cave. Transformers, asphalt trails, and cabins were removed to prevent sewage or oils from leaking into the cave from the surface. Thousands of formations buried under rubble were uncovered. Crystal clear water once again cascades over white marble. Some broken formations have been repaired with epoxy and powdered marble. Airlocks have restored natural cave winds by blocking airflow in artificial tunnels. Spraying with bleach keeps the algae under control. The new lighting and trail system will reduce evaporation and unnatural foods, which have attracted surface insects and drive out native species. Not everything has been or can be restored. For example, the dissolution and formation of cave decorations are in delicate balance with the amount of carbon dioxide in the air and water. A global increase of this gas in the atmosphere, caused largely by deforestation and burning of fossil fuels, is affecting this balance. Still, one can now see a renewed cave, a valuable benchmark against which we can measure human impacts, now and in years to come.

Cave Geology: Exploring Underground

A tour through Oregon Caves is an adventure in geology. A myriad of calcite formations decorate the cave. You will find striking parachute-like flowstone at Paradise Lost and what appear to be giant ribs as you squeeze through the Passageway of the Whale. Tiny rimstone dams resemble miniature waves on the sea.

It is the drip, drip of water that decorates the cave, building the bizarre and eerie sculptures. How the water moves – seeping, dripping, flowing – and how many crystals come out of the individual drops of water dictate the shape and size of formations made of calcite, the same mineral found in cement and eggshells.

Some formations provide information about the cave. Water evaporated by air flowing in from outside leaves a residue of bumpy cave popcorn. Cavers use popcorn as a compass to find new passages or, when lost, their way out. Moonmilk is made of tiny calcite crystals but has the look and feel of cottage cheese. From early times it was a folk medicine smeared on livestock to heal wounds and is created by the same type of bacteria used to make today’s antibiotics.

Rising warm air condenses on the cold ceiling and is acidified by carbon dioxide in the cave. This water dissolves formations, leaving behind cave ghosts, the nubbins of former stalactites.

Touring the Cave

Touring Oregon Caves has been a tradition more than a century. Guides lead you through a one-half mile marble passage and discuss the cave’s natural and cultural history and its preservation. Tours are scheduled regularly in spring, summer, and fall. No cave tours are offered during the winter months (December through February). A fee is charged, and prices are subject to change. Tours last about 75 minutes. Waiting times can reach 90 minutes in the summer.