Ape Cave in the Gifford Pinchot National Forest near Cougar, Washington (USDA photo by Cecilio Ricardo) Ape Cave is the third longest lava tube in North America at 2.5 miles. A 3/4-mile, paved family-friendly trail goes to the lower cave. For a bigger challenge, the 1.5-mile upper cave trail leads to a climb up an … Continue reading Ape Cave reopens via timed reservations May 18