Termed Oregon's Marble Halls, Oregon Caves National Monument features complex marble cave systems, rare plants and animals, and outdoor adventures.
Oregon Caves National Monument is small in size, 480 acres, but rich in diversity. Above ground, the monument encompasses a remnant old-growth coniferous forest including a Douglas-fir tree with the widest known girth in Oregon. Three hiking trails access this forest. Below ground is a marble cave created by natural forces over hundreds of thousands of years in one of the world's most diverse geologic realms.