Ape Cave Lava Tube
Mt St Helens National Volcanic Monument
Follow the signs off Forest Service Rd 90, north of Cougar
Ape Cave is a lava tube on the south side of Mt. St. Helens. At 2.5 miles long, it is the longest continuous lava tube in the United States. It is open for hiking, but be prepared for loose rock, rough surfaces and darkness.
Lava tubes are unusual in the Cascades because the Cascades volcanoes are mostly stratovolcanoes and thus do not usually erupt with fluid rock (pahoehoe). Ape Cave's length is especially noteworthy for that reason.
Entrance to Ape Cave (O04A0259)
Inside Ape Cave (O04A0263)
The flashlight that I keep in the car is not adequate for caving purposes, so I stayed near the entrance when I headed down into Ape Cave lava tube.
You may also like these Mt. St. Helens destinations:
- Johnston Ridge Observatory, Mt St Helens National Volcanic Monument, Washington
- Windy Ridge Observatory, Mt St Helens National Volcanic Monument, Washington
- Lava Canyon, Mt St Helens National Volcanic Monument, Washington
While you're in the area, check out these sights:
- Fort Vancouver National Historic Site, Vancouver, Washington
- April Snow At Paradise, Mt Rainier National Park, Washington
- Hiking At Sunrise, Mt Rainier National Park, Washington