The talus slope to your right is formed primarily of debris from lava flows and maar deposits. As the basalt lava solidifies cooling cracks develop. These fractures are known as columnar joints. The cracks form block-sized hunks of basalt that eventually tumble downslope forming the talus. This particular rockfall, as documented by historic photographs, happened in 1942.
Falls Trail Stop 18
Last updated: February 24, 2015