Subway Cave is a lava tube that was formed during volcanic events just twenty thousand years ago, but today it offers an unusual hiking experience in an area of very interesting and recent geologic activity. The trailhead is located less than half a mile from the junction of Highway 89 and Highway 44 in Old Station.
Subway Cave was created when large amounts of lava were flowing across all the area around the present-day location of Hat Creek. The lava on top, exposed to the air, cooled and formed a hard cap while molten lava continued to flow beneath. Eventually, the molten lava drained away but the hollow tubes remained. This hike lets you follow in the footsteps of these relatively recent lava flows.
The parking area features picnic tables and toilets and the entrance to the cave is a short walk away and well marked.
A flight of stairs descends into a gaping hole in the ground and meets a fairly level floor of the cave that runs its entire length. The floor is rough in many places, so sturdy shoes are recommended. The walls and ceiling of the cave are smooth and lead into the complete darkness that greets hikers on this walk.
Be sure to bring a flashlight if you want to walk the less than half a mile length of the cave. The temperature inside the cave remains a constant 46 degrees year round, so you might want a light jacket even in the middle of the summer. Interpretive signage can be found at the trailhead in some locations inside the cave, which help explain the unusual site.