Mount St. Helens Ape Cave Lava Tube

is a popular attraction in the Mount St.

Helens National Monument and the longest lava tube in the continental United

States at

over two miles in length

.

The Ape Caves are located on the south

side of Mount St. Helens and accessed through Woodland - go up highway 503

past Cougar. Driving time from I-5 and highway 504 where all the Mount St.

Helens Visitor Centers are to the Ape Cave is just over an hour. The Ape Caves

are open year-round though the parking lot gets snowed in during the winter.









































































Hiking the Ape Caves:

The lower Ape Cave is approximately is .75 miles long

and can be hiked down and back in an hour. It is most famous for

“Meatball”

- a

block of cooled lava which fell from the lava tube ceiling while lava was still flowing

through the cave. Floating on the surface of the lava flow it was carried

downstream until it became wedged in a narrow spot above the present cave

floor.































Another feature is the

“Railroad tracks”

– a shoulder or levee that formed along

the side of the lava flow. As the fluid lava drained out of the tube, the levee

remained. Lava stalactites and stalagmites and flow marks can be seen on the

walls and floor of the cave. Lava stalactites, conical or cylindrical deposits of lava

that hang from the ceiling of a tube, are formed by dripping; stalagmites are similar

in shape and are formed on the floor of the tube by the accumulation of drips from

the ceiling.





















The upper Ape Cave is 1½-mile long and takes about 2½ hours to complete,

returning on a surface trail. This section is more adventurous as cavers must climb

over approximately 27 boulder piles and scale an 8-foot high lava fall. The

boulder piles formed after the eruption subsided and the fluid lava drained from

the tube. As the lava tube cooled, it began to shrink and crack. These cracks

weakened the ceiling and walls causing parts of them to collapse – forming

entrances to Ape Cave. Note there is a skylight hole in the tube near the upper

exit however the trail continues on through the tube to a permanently attached

metal ladder. Exiting the cave through the skylight is off limits. During the

summer, a national monument interpretive naturalist leads tours through the lower

part of the cave. Recommended equipment for exploring the Ape Caves is sturdy

shoes or boots, warm clothing, and three sources of light.





Ape Cave Hiker USFS Regulations:





No food, beverages, alcohol or

littering .



No smoking , No flares, fireworks,

firearms or any kind of open flame



No rock collecting or damaging cave

features ($200 fine).



No pets !



Do not touch the walls - Cave “slime”

lives on the cave walls and is an

important food source for cave life.







How the Ape Caves were formed:

About 2,000 years ago lava poured down

the southern flank of Mount St. Helens in streams. As the lava flowed the outer

edges of the lava stream cooled forming a hardened crust which insulated the

molten lava beneath. This allowed the lava to remain hot and fluid encased in this

“lava tube” and continued flowing months during the eruption. The end result was

the creation of this spectacular 13,042 long lava tube. This formation is especially

unusual at Mount St. Helens as this type of volcano usually erupts lava of a much

thicker consistency which tends to block flow and build up pressure resulting in

explosive eruptions like the blast of 1980.





Watch out for the Wild Apes !

Mount St. Helens has long been famous as an

area of frequent Bigfoot, Sasquatch or “Hairy Ape” sightings.





Nearby “Ape Canyon” was the sight of the famous reported

skirmish between Miners and a family of Bigfoot back in 1924.

The incident has become a legend in the Northwest – here is

the bigfoot story from one of the miners - " I FOUGHT THE

APEMEN OF MOUNT ST. HELENS, WA". However, I wouldn’t

worry too much about seeing bigfoot in the Ape Caves –

common lore attributes the name to a scout troop who explored

the caves back in the early 50’s. Apparently the troop’s

sponsor was the St. Helens Apes – a group of foresters.



Foresters and loggers in those days were sometimes referred to as “Brush

Apes”. Perhaps this is the origin of the name though those that have claimed to

have seen bigfoot in the area believe the caves would have been a perfect habitat

for the reclusive creatures.





Ape Cave Vicinity Map:

