This National Monument in the Pacific Northwest Was Just Named a Dark Sky Park — and It Has Stunning Marble Caves, Too

Months after the Oregon Outback was recognized as the world’s largest International Dark Sky Sanctuary, a new Oregon park joined the “Dark Sky” ranks. On Nov. 14, 2024, Oregon Caves National Monument and Preserve was recognized as the state’s latest dark sky destination following a three-year night sky monitoring program and a comprehensive in-park lighting assessment.

The news will bring stargazers to the Siskiyou Mountains of southwestern Oregon where the 4,554-acre Oregon Caves National Monument and Preserve sprawls. The park, which is now recognized for its inky black skies, has long protected a sprawling system of caves and passages that offer their own brand of darkness.

The caves, nicknamed the “Marble Halls of Oregon” are rare in North America. They were formed over millions of years by slightly acidic rainwater that slowly dissolved limestone and marble, carving out a massive series of underground passages and chambers. The constantly evolving and changing cave system also includes various mineral formations, including stalactites, stalagmites, flowstones, and helictites. 

Oregon Caves National Monument and Preserve lets visitors see and experience this underground world through guided cave tours that run from late spring to early fall. The monument currently operates four types of underground tours, including an excursion aimed at kids and families to trips by candlelight and tours that go off-trail into the depths of the Earth. While exploring the cool caverns and passageways below the surface of the Earth, guests learn about the geology, history, and wildlife of the caves (the latter includes the rare ghost shrimp).

One of the most sought-after underground sights in the monument is the “Ghost Room,” a large chamber filled with various mineral formations that visibly showcase the ongoing change taking place under the surface of the Earth.

Meanwhile, above ground, travelers are treated to views of the Siskiyou Mountains from the preserve’s various hiking trails. Some routes cut through old-growth forests, like the 1-mile-long Old Growth Trail, while others lead to the summit of local mountains, like the 8-mile hike up Mt. Elijah. On one of the monument’s hiking trails, you might even spot some local wildlife. The preserve is home to black bears, deer, owls, and Pacific giant salamanders, along with a population of rarely seen mountain lions. 

Oregon Caves National Monument and Preserve was established as a monument in 1909 but grew to encompass the surrounding wilderness in 2014. It is located 35 minutes east of the city of Cave Junction, on Oregon Route 46. 

The Oregon Caves National Monument and Preserve is open year-round and access is free, but the cave tours are only available between late spring and early fall and require the purchase of a ticket. You can reserve your in-season cave tour through Recreation.gov or by purchasing a same-day ticket at the Illinois Valley Visitor Center in Cave Junction.