Trail #239 Ape Cave

Area Status: Open
This area is Open

The above ground Ape Cave Trail #239 provides an easy return route, except during the winter season, to the main entrance and Ape's Headquarters after hiking the upper cave route. Today the cave is a popular visitor attraction, with many thousands of visitors annually.

At a Glance

Current Conditions: 3/19/2019: 3 feet of snow on the trail. Forest Road 8303 to Ape Cave gated at Trail of Two Forests Sno-Park. Visitors must walk 1 mile through snow to the cave entrance. A Washington State Sno-Park permit is required to park and NOT available on-site. Cave open during daylight hours. No pets, food or drink allowed inside the cave, except water. Bring two light sources per person. Upper cave not suitable for children.
Permit Info: A Sno-Park permit is required at Trail of Two Forests Sno-Park during the winter season. Sno-Park permits are not available on-site.
Usage: Medium-Heavy
Best Season: Summer
Busiest Season: Summer
  • Pets, smoking, fireworks, and food are prohibited in the cave.
  • Please leave pets at home, hot summer tempatures can be deadly for pets left in cars.
Closest Towns: Cougar, WA
Water: No
Restroom: Vault Tolilets
Passes: A valid Recreation Pass is required at Ape Cave Trailhead.
Operated By: Forest Service
Information Center: Mount St Helens National Volcanic Monument Headquarters and Visitor Centers

General Information


From Cougar, WA drive east on Forest Road 90. Then just 1 mile beyond the Swift Dam turn left (north) onto Forest Road 83. Drive 2 miles on Forest Road 83 and turn left onto Forest Road 8303. Continue for 1 mile on Forest Road 8303 to the trailhead on the right.

Note: To protect big game habitat, Forest Road 8303 is closed to motorized use during the winter months. Plan to park at the Trail of Two Forests Trailhead and hike or snowshoe the 1 mile to the cave in winter.



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The lower cave is the more popular route with its fairly level, mudflow-covered floor. Highlights include “railroad tracks” and the "meatball." Allow at least an hour to complete the 1.6-mile round trip.

The upper cave travels over large rock piles and requires scaling of an 8-foot lava fall. Two-thirds of the way up you will pass beneath The Skylight, an opening to the surface. Do not try to climb out; this is NOT an exit. The upper exit is only 0.25 mile ahead. The upper cave is not recommended for small children.

Allow 2.5 hours for travel through the upper cave to Ape Cave Trail #239. The above ground Ape Cave Trail #239 provides an easy return route to the main entrance and Apes’ Headquarters.

Related Information

Areas & Activities



  Area/Length : 
Lower Ape Cave: 0.8 milesUpper Ape Cave: 1.5 milesApe Cave Trail: 1.3 miles

  Elevation : 
1800' - 2500'


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