Oregon Caves National Monument

Few caves in the National Park System offer a more stunning array of geological formations than Oregon Caves. Known as the "marble halls of Oregon," the rare marble cave was proclaimed a national monument in 1909. All six of the world's major rock types are found in the cave, along with a crystalline substance called "moonmilk." The substance, which looks and feels like cottage cheese, is composed of the same type of bacteria used to make antibiotics. People in the nineteenth century discovered that smearing moonmilk on wounds made them heal almost magically.

Oergon Caves National Monument
©National Park Service
A stunning array of geological formations can be found at Oregon Caves
National Monument.

Many different types of ever-changing formations fill the cave. Pendant decorations hanging from the ceiling are called stalactites. Formations growing up from the floor are stalagmites. Sometimes the two meet and fuse, forming a column. Dripstones decorate the walls where water drips into the cave. Graceful formations called flowstone were slowly deposited as water seeped quietly over walls and floors.

Oregon Caves were discovered in 1874 when local rancher Elijah Davidson followed his dog into an opening in the mountains while chasing a bear. The cave quickly became a popular spot for tourists.

Tours provide a look into the cave's geology, ecology, and inhabitants. Cave creatures include the Townsend's big-eared bat and numerous blind, colorless insects. A grasshopper-like species found here in 1989 is believed to be unique to Oregon Caves. To find out what kind of creatures live in the cave, park rangers set out traps baited with Limburger cheese. Wildlife also abounds outside the cave. Black-tailed deer, porcupines, and giant Pacific salamanders inhabit the lush Siskiyou National Forest that surrounds the cave. Nature trails lead past mountain streams, mossy cliffs, fields of wildflowers, and a 1,500-year-old Douglas fir that is 40 feet around. The Cliff Nature Trail, which climbs to an elevation of 4,000 feet, provides panoramic views of the countryside.

For a century after the Oregon Caves were discovered, tour operators with good intentions nearly destroyed the cave. To accommodate very large numbers of tourists, they laid down asphalt paths and installed bright lights in the cave. Unfortunately, their efforts were harming the cave's environment.

For several years now, the Park Service has been working to restore the cave to its original condition. Because asphalt attracts exotic organisms as it decays, all the old paths are being replaced with high-tech walkways, and lower-wattage lights will replace the bright bulbs that encourage moss and fungus growth. The changes will improve air flow in the cave so stalactites and stalagmites won't freeze and break in the winter, and cave creatures can move about more freely.

Oregon Caves National Monument Information

Address: 19000 Caves Highway, Cave Junction, OR
Telephone: 541/592-2100
Hours of Operation: Open daily except Thanksgiving and Christmas; call for tour times
Admission: Cost of tours varies

Learn about these other national monuments:

­Agate Fossil Beds National Monument

Colorado National Monument

George Washington Birthplace National Monument

Natural Bridges National Monument

Scotts Bluff National Monument

Alibates Flint Quarries National Monument

Devils Postpile National Monument

George Washington Carver National Monument

Ocmulgee National Monument

Sunset Crater Volcano National Monument

Aniakchak National Monument and Preserve

Dinosaur National Monument

Gila Cliff Dwellings National Monument

Oregon Caves National Monument

Timpanogos Cave National Monument

Booker T. Washington National Monument

Effigy Mounds National Monument

Grand Portage National Monument

Organ Pipe Cactus National Monument

Tonto National Monument

Buck Island Reef National Monument

El Malpais National Monument

Hohokam Pima National Monument

Petroglyph National Monument

Tuzigoot National Monument

Cape Krusenstern National Monument

El Morro National Monument

Homestead National Monument

Pinnacles National Monument

Walnut Canyon National Monument

Capulin Volcano National Monument

Florissant Fossil Beds National Monument

Hovenweep National Monument

Pipe Spring National Monument

Wupatki National Monument

Casa Grande Ruins National Monument

Fort Frederica National Monument

Jewel Cave National Monument

Pipestone National Monument

Castle Clinton National Monument

Fort Matanzas National Monument

John Day Fossil Beds National Monument

Poverty Point National Monument

Cedar Breaks National Monument

Fort Stanwix National Monument

Lava Beds National Monument

Rainbow Bridge National Monument

Chiricahua National Monument

Fossil Butte National Monument

Montezuma Castle National Monument

Russell Cave National Monument

To learn more about national monuments, memorials, and historic sites, and other travel destinations in North America, visit:


Eric Peterson is a Denver-based author who has contributed to numerous guidebooks about the Western United States.