Skull Cave

Skull Cave lies at the end of a paved road in Lava Beds National Monument, on the line of collapse trenches and caves that skirts the south side of Schonchin Butte in far northern California. It is one of the park's least challenging caves and one of its largest, a wide, open place for anyone who dislikes tight spaces. The entrance sits at the east end of an impressive collapse trench 460 feet long and 100 feet wide, and the upper level beyond it is a huge tunnel 60 to 80 feet wide and 30 to 65 feet high. So much of its roof, floor and walls has fallen in that most of its original form is lost, and the floor is a jumble of collapsed blocks.

The cave is a remnant of great feeder tubes stacked one on top of another, which carried vast quantities of lava from the vents of Mammoth Crater toward the lowlands of Tule Lake, about 15 miles away. The park counts three tubes; a US Geological Survey bulletin counted two, with balconies marking pauses as the lower tube drained. About 480 feet in, the upper tube ends abruptly at a semicircular wall where the lava found its way down into the level below, and a remnant of that flow survives as a frozen lava fall, visible from the base of the first stairs. The stacked tubes trap cold winter air, so the lower level holds a floor of ice all year, reached by a smooth trail and a metal stairway down to a viewing platform.

The name comes from what the first modern explorer found there. In 1898 E. L. Hopkins spotted the long trench from the top of Crescent Butte, went to investigate, and found on the lower level, partly embedded in the ice, two human skeletons and a great many bones of antelope, bighorn sheep and mountain goats. A broken log lay on the ice beside them. The survey's reading was that two people had tried to lower the log as a ladder, let it slip, and been swept off the balcony to their deaths. Beyond a narrow crawl over a pile of fallen roof lies a second chamber that spelunkers, hoping for another hoard of bones and finding none, nicknamed Boneless Cavern.

Bats use the monument's caves through the year, at least 14 species of them, and rangers ask cavers to keep quiet and keep their lights off any they find.