The entrance is underneath a trapper outpost. The outpost is guarded by some trappers and one machine gun turret. It also has cooking and chemistry stations. Upon entering, the player character will follow a brief tunnel before coming to a barricade with an Easy locked door on the left and an open path on the right.
Beyond this is a well-defended trapper fort. The right path runs through a shooting gallery with many trappers above, shooting from all sides, with a tripwire across a small wooden walkway. The left goes to the top of the fortifications and is a good path to sneak up on their flank.
The right path features a long display of uniquely mutilated corpses with impaled heads connected to their dangling skeletons, an unfortunate victim hanging from four chains with his head and upper spine dangling below, and one victim growing a blight mushroom out of his torso.
At the back of this fort is a tunnel filled with can chimes, another turret, and a tripwire right before a doorway connecting to Kitteredge Pass, which then drops off into the small pool, rendering Pine Crest Cavern inaccessible from the interior of Kitteredge Pass without jet pack equipped power armor.