Ape Cave

Cougar, WA
Length: 1.50 mi.
Type: Loop

About This Trail

[Total: 4    Average: 2.5/5]

The Ape Cave is the third longest lava tube in North America, spanning 13,042′ long. A short, paved trail leads from the parking lot to the cave’s lower entrance. Once you reach the entrance, you’ll descend two staircases to the floor of the cave and meet the junction between Upper and Lower.

The Upper Cave is a rugged, 1.5-mile hike through rock piles, ledges, and fascinating formations. Be cautious where you step and watch your head through this area. The largest challenge comes about 0.8 mile in. There is a tall lava fall that you will need to climb over. A foothold is present, but it’s easiest if you have someone give you a hand. As you near the cave’s exit, you’ll be greeted with a “skylight”, a natural hole in the cave allowing the sun to beam down on you. Slightly farther down the cave, you’ll come to the metal staircase exit. After you climb out, you’ll enjoy a mild hike through the forest back to the parking lot. The trail includes blue diamond snow markers to follow.
For a milder adventure, you can explore the Lower Cave. It’s a wide tube with a mostly flat floor that provides a 1.5-mile roundtrip walk.

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Trail Features

Seasons Fall, Spring, Summer, and Winter
Surface type Mixed
Stroller friendly No
ADA accessible No
Water fountains No
Bathrooms No
Cell reception None
Pet friendly No
Nearby convenience store No
Camping Nearby No
Emergency support
within 5 miles

Trail highlights

Camping Nearby, Mud Puddles, Natural Play Area, Rockclimbing, Shaded Hike, and Visitor Center

The parking lot has room for 50-60 vehicles, including bus and RV spots. There are vault toilets and garbage cans, but no drinking water. When it’s open, Ape Headquarters Center offers rental lanterns.
Be sure to bring sturdy shoes, warm clothes (temps around 42°F), and two light sources per person.
Practice Leave No Trace. This cave is a delicate ecosystem.
• Wipe your feet before you enter the cave
• Do not touch the walls or “slime”.
• Watch for mud puddles.

Fee & Parking Details

Fee : $5.00

NW Forest Pass required- $5 per car or $30 annual

A Sno-Park permit is required from December 1 through March 31.

Trail Contributor

[Total: 4    Average: 2.5/5]

Being outside is how I re-charge. It gives me perspective, fills me with gratitude and provides an opportunity to disconnect from the chaos of everyday life. I am fortunate to share this passion with my amazing husband and our son.  I was born and raised in the PNW but I love exploring any area I can get to. One of my favorite things about Hike it Baby is that I have a built in community of friends to provide trail suggestions anywhere we go.


Trail Head


Trail Map

Getting There

From I-5 exit 21, travel north and east on State Route 503 (Lewis River Road). Approximately 23 miles down, continue straight on Spur 503. At 31 miles, Spur 503 becomes Forest Road 90. Cross a bridge over a canal, then 2.6 miles later, turn left on FR 83. Travel 1.7 miles then turn left on FR 8303. Travel the final mile to the parking lot and Ape Headquarters Center.