View from about 600' inside Petlog Cave, a rarely visited lava tube in the Medicine Lake Volcano area of Northern California.  The cave has a couple of initial breakdown openings & this lower-elevated passage goes for about 1,500 feet w/in & contains a well-preserved passage w/ minimal breakdown.  It is part of the same cave system as Harvestmen Cave which is just up the slope.  The unique feature of this cave is this section of shelf that resembles a petrified log.