A Southern Washington Lava Tube, July 2023.
This cave is possibly the second-longest lava tube in North America. It's somewhat known by locals, so unfortunately bears the scars of visitation by an unknowing, uncaring public. Lava caves cannot clean themselves out, nor can they regenerate.
It's a more complex lava tube than most - it has at least three branching passages above the main channel. Two are meanders from when the flowing lava river was at a higher level, and another is a channel that branches off downstream. I cannot find a modern survey of it, so the true length of these branches and the cave itself is unknown to me. The entrance of the cave is steep, and the opening is small. The setting allows a moss and fern garden to grow green in the misty daylight until it is choked out by the dark.
This cave surprised me with how tall and narrow it is - ceilings are often in excess of 40 feet (~11 m), carving a winding void into the earth. The floor is very rugged, and made of breakdown (collapse debris) for most of its length. We never reached the end, unprepared for how long it would take to finish the remaining third of the cave. A return is in order after the thaw.
