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Two self-guiding interpretive trails wind through the heart of the Modoc's wartime defenses. The inner loop is 0.5 miles (0.8 km), and the outer loop 1.5 miles (2.4 km). Be prepared for rough terrain.
(770 ft/235 m). Recommended as an introductory cave. This cave has lights and interpretive signs explaining the formations.
(3,280 ft/1,000 m). This cave's easy main trail requires no stooping or ducking, and has lots of interesting features. This is one of the only developed caves with two entrances.
(1,635 ft/498 m). This cave was discovered on Valentine's Day in 1933, and has large main passages with very smooth floors and walls. It had a different lava source than the caves on Cave Loop.
(580 ft/177 m). Named for the bones of antelope and mountain goats, bighorn sheep skulls, and two human skeletons discovered inside. It is a remnant of two very large lava tubes, one on top of the other. This allows cold winter air to be trapped inside and create a year-round ice floor on the lower level, accessible via a smooth trail and down a metal stairway to a platform.
(650 ft/198 m). Visitors once ice skated by the lantern light on an enormous ice floor at the bottom of this cave. Changing air flow patterns are the suspected cause of melting, and today you can see small ice remnants from a viewing platform at the bottom of a stairway.
(170 ft/52 m). Walk a short trail to this short twilight-lit cave with a small pool that is frozen most of the year. A spatter cone, huge collapse pit, and several other short cave passages can also be explored nearby.