Rating:
Area: Lassen
Distance: <1 mile
Type: Loop
Difficulty: Easy

Part of our Lassen Volcano Country special feature. Some Lassen hikes are often closed due to winter weather, so check out the conditions before you go by following the above link.

Twenty thousand years ago the ground north of Lassen broke apart and huge volumes of volcanic rock poured out, creating the enormous expanse that is the Hat Creek lava flow.

Cooling when exposed to the air, the top of a lava flow solidified stop while molten rock beneath continued to flow. The solid roof of the flow insulated the still hot magma, and acted as a conduit, carrying red-hot rock miles from its source. When exhausted all that remained was the cool solid rock conduits known as lava tubes, large enough to walk through.

You'll need to bring a flashlight with you to explore the quarter-mile long Hat Creek tube known as Subway Caves, which are open from May through October. Easy to hike and navigate, the route through the caves begins and ends with staircases, and an above-ground return trail leads you back to the large parking lot.

Tangents:
- US Forestry Service: Subway Caves
- US Forestry Service: Guide & Map (PDF)
- Wikipedia: Lava Tubes
- The Virtual Lava Tube
* add your flickr photos to the gallery with the tag trailspottingsubway