The Only ‘Wild and Scenic’ Subterranean River

In Greek mythology, the River Styx forms a border between the underworld and the world of the living. Charon, the ferryman, would collect payment from souls to transport them to the far side, and some people believed the river contained magical properties — including the mother of Achilles, who dipped the future warrior into its waters but forgot to submerge the baby’s heels. But that’s another story.

At Oregon Caves National Monument and Preserve, visitors get to explore a different kind of underworld and can see the River Styx without selling away their souls. The park site, located in the Siskiyou Mountains of southern Oregon, features one of the few marble cave systems in the United States. The cave passages measure about 15,000 feet in length, about as long as Washington state’s Mount Rainier is tall.

Visitors can sign up for cave tours for a modest fee to explore the park site’s depths, or they can stay above ground and enjoy old-growth forests, meadows, diverse wildlife and scenic mountain vistas.

The River Styx begins as Cave Creek before disappearing underground, where it runs a half mile through marble bedrock. In 2014, the River Styx became the first totally underground stream to be added to the National Wild and Scenic Rivers System, which protects waterways in their free-flowing condition. It remains the system’s only subterranean river.

The River Styx flows continuously year-round with a temperature of about 41 degrees Fahrenheit, while the air temperature is about 44 degrees. The cave’s ecosystem depends on the river’s pristine water, which resurfaces within the park site’s boundaries with the name Cave Creek and eventually flows into the Illinois River and onward to the Pacific Ocean.

At 220 feet underground, two small tributaries on the floor of the cave’s Ghost Room join to form what is called the Ghost Styx — so named because the waterway seems to disappear back into the bedrock. It rejoins the main River Styx deeper in the cave.

There are no fish in this stream — water entering the cave from Cave Creek must pass through ground soil that filters out any fish or organic matter that would sustain them. In fact, a non-toxic dye was once added to the creek to see how long it would take to reach the River Styx’s accessible sections inside the cave, and it took two days.

Only one water mite and a caddisfly are known to live in its water, while more than 340 different species have been documented in the cave itself. Research by National Park Service scientists shows that chemical reactions from the river continue to enlarge the cave.

Adding to the river’s curiosities, the upper Cave Creek often dries up during the summer, yet the River Styx continues to flow, indicating there must be other water sources that join the River Styx inside the cave. Also, a portion of the river as it exits the cave diverts through the dining room of the six-story Chateau at Oregon Caves National Monument, a 1930s-era National Historic Landmark currently closed for repair and rehabilitation.

Hunter Elijah Davidson stumbled upon the cave in 1874 while chasing his dog and a bear, although the Takelma people, who lived in what is now known as the Illinois and Rogue River valleys, were likely aware of the cave system long before.

President William H. Taft established the cave system and intricate underground passages, chambers, tunnels and geological formations as a national monument in 1909. A park ranger came up with the stream’s name in 1911. There are stories of that ranger — Dick Rowley, who worked at the national monument for 54 years — hiding in the cave and howling like a wolf as tour groups would pass.

When Taft created the national monument to protect the rare cave system, the area above ground and much of the marble block supporting the cave and Cave Creek headwaters weren’t included. That’s because people of the early 20th century didn’t understand the ecological connection between caves and their surface environment.

Scientists now understand how strongly the two are connected. So in 2014 with support from NPCA and private donations, the National Park Service purchased 4,000 acres of grazing leases in the watershed above the cave to protect the river from pollution. This land became the Oregon Caves National Preserve and led to the River Styx’s designation within the National Wild and Scenic Rivers System.

Want to visit?

There is no charge to enter Oregon Caves National Monument and Preserve, but the only way to experience the caves is through a fee-based guided tour offered late spring to early fall. The cave is closed in winter to protect hibernating bats, but the park’s surface areas are open year-round. Visitors are encouraged to stop at the Illinois Valley Visitor Center in Cave Junction, Oregon, before making the nearly one-hour, narrow and winding drive to the on-site Oregon Caves Visitor Center.