Kulana'ahane Trail

The Kulana'ahane Trail offers unparalleled hiking through native Hawaiian forest to a scenic overlook. It is only accessible by hiking approximately 2.5 miles up the Kamananui Valley Road Trail, where a marked sign on the left designates the trailhead. The Kulana'ahane Trail adds 5.5 miles for a total hike of 10.5 miles out-and-back from the parking area at the bottom of the valley. The Kulana'ahane Trail begins by immediately crossing the Moanalua Stream, crossing it 28 more times before heading up the steep ridge to a panoramic viewpoint of the Haiku Valley and the windward side of the island. It is not recommended to hike this trail during heavy rains, as flash flooding is common. 

Follow the trail, passing by a couple pleasant swimming holes, through dense hau groves and by native hapu'u fern trees. When passing through the hau groves, their low canopy will require you to crouch. Keep an eye out for metal pieces that were swept downstream from an F-47N Thunderbolt plane crash further up the valley. The plane crashed back in the late 1940s after the engine caught fire, forcing the pilot to ditch the aircraft. 

At the last stream crossing, there is a sign marking the end of the maintained trail. The last quarter mile is a steep, narrow, and slippery trail to the top of the ridge with approximately 600 feet of elevation gain, terminating in a washed-out lookout over the H3 Highway. On the way up the spur ridge, notice the native 'ohi'a lehua 'ahihi trees (Metrosideros tremuloides), which are only found at higher elevations on O'ahu. Continuing along the Moanalua Saddle is dangerous as the ridge is heavily eroded and unstable, so hikers are urged to stop at the lookout; many have fallen to their death attempting the ridge in pursuit of the prohibited Haiku Stairs.

Alternatively, instead of climbing the steep ridge, hikers can access the waterfall at the back of the valley by taking an overgrown path that branches off to the right approximately 30 feet past the un-maintained trail sign. This trail follows the riverbed before reaching the waterfall. Colorful tape can be seen marking branches along the way. Just below the waterfall pool is the surprisingly intact propeller and engine from the Thunderbolt plane wreckage that slammed into the mountain cliffs above. 

If you plan to hike this trail, allow for ample time to go out and back, as the park closes at exactly 7 p.m. The trail is open to backcountry camping with proper permits from the state; reservations can be made online. Overnight parking is not allowed in the Moanalua Valley Neighborhood Park. Campers must find legal parking in the adjacent streets. Do not leave valuables in your car.

Note that streams in the Moanalua Valley are prone to flash flooding. Waters may rise with little or no warning. Check weather conditions before attempting. Do not attempt if it has been raining recently.