📜 Longest continuous lava tube in continental U.S.
🔍 Formed over 2000 years ago by lava flows from Mt. St. Helens.
🌋 Explore a unique lava tube formation
🚶♀️ Choose between easy or challenging routes
🧊 Experience constant 42°F (6°C) underground temperature
📸 See stalactites, stalagmites, and an 8-foot lava fall
⚠️ Reservations required May-October
🚫 No food, pets, smoking, or rock collecting allowed
👶 Upper cave not recommended for small children
🔦 Requires multiple light sources and sturdy shoes
🧤 Bring gloves and long pants for the challenging upper cave.
💡 Headlamps are highly recommended for hands-free exploration.
🚗 Save offline directions as data connections can be unreliable.
Northwest Forest Pass or Sno-Park permit required.
Daily 5:00 AM - 9:00 PM; cave open to public May-October.
Large lot available for vehicles, buses, and RVs.
Vault toilets and garbage cans on site.
Last updated 9 days ago
We strive for accuracy, but errors may occur. Please verify key info.