El Malpais National Monument
To get to the Big Tubes Area:
- Drive 26 miles west on SR 53 to CR 42 south.
- There are two roads that allow access to the Big Tubes Area parking lot. They are located 5.5 and 6.5 miles south of SR 53. A cairn trail will lead you to Big Skylight and Four Windows caves.
A high clearance or four-wheel-drive vehicle is needed to visit this remote section of the Bandera Lava Tubes system. Travel in this area is discouraged when roads are wet. Please respect private land by closing all gates and staying on designated roads and trails.
Hard hats, boots, protective clothing, gloves, water, and three sources of light are necessary when entering lava tubes. Please be careful!
Big Skylight Cave
The large opening in the roof gives this 600-foot-long cave its name. Near the entrance and the skylight, the cave is approximately 60 by 50 feet high. Under the skylight, a bed of green moss grows all year due to the light and changing seasonal air currents. The walls have conspicuous horizontal striations formed by fluctuating levels of molten lava that flowed through the cave. The large blocks of lava that fell from the ceiling sometime after the lava completely hardened, make travel in this cave a challenge. Following either wall will bring you full circle back to the entrance.
Four Windows Cave
Because openings in the roof of this cave are much smaller than in Big Skylight Cave, they are called "Windows." This cave measures approximately 50 feet in both directions near the entrance. The character of this cave changes from large ceiling rubble, covered by moss under the windows, to smooth floor in the Cauliflower Passage, to small ceiling rubble in One-Foot-in-the-Gutters Gallery, to crawl ways and rubble near the north exit. In the Cauliflower Passage, you will walk on the original ropy lava floor. A smaller side passage, west of the Cauliflower Passage can be negotiated if you are not claustrophobic!
A "collapse structure'' is a portion of a lava tube where the roof has caved in, creating a trough. Small collapse structures also formed where lava bubbles popped. The outline of this collapse looks like a caterpillar. At the north end, a later lava flow merged into the collapse.
This is the highest wall of lava at El Malpais: over 100 feet in places. Small pockets in the wall collect and hold moisture. Plants that are unusual to this elevation and rainfall, such as aspen, take advantage of this micro-climate.
Details mentioned in this article were accurate at the time of publication