We usually park our cars along the highway across from Waikane Valley Road and begin hiking from there. It is also possible, for those with 4x4 vehicles, to drive a mile up the valley to cut down on some road walking. For the sake of this write-up, I'll assume a start from the highway.
The initial road walk will take you past several houses and a church on the left. Not far past the church, a gated road on the right is the way to proceed. In recent times, the gate has been open. Even if locked, the gate is easily bypassed by those on foot.
At the next junction on the dirt road, head right downhill. The road straight ahead is wider and may look more well-used but heading right is the way. Eventually, the road will cross a stream and then reach another gate, which has been locked the half dozen times I've passed it. Those with sturdy vehicles can drive to this gate and commence hiking there, saving a half hour of walking.
Of interest in this next section of road is a segment of the Waiahole Ditch Trail, which joins the road from a slope on the left, and the site of Waikane Camp, located on the left at the head of a ravine where the road makes a sharp bend. Not far past Waikane Camp (it's possible to pass it and not realize it), the road forks. Take the left fork and almost immediately reach an intake tunnel of Waiahole Ditch, with the sound of gushing water in the ditch to indicate you've reached this landmark. On foot, 45 minutes to an hour is what is usually needed to reach the ditch from Kam Highway.
The ditch is good place to rest and regroup, for from there the climb to the Koolau summit commences in earnest. To the left of the ditch tunnel is the continuation of the Waiahole Ditch Trail. Follow it as it heads to the back of the ravine and then climbs out of it. The trail continues to climb steadily, winding in and out of a couple of ravines as it does. About 20 to 30 minutes from the ditch tunnel, the saddle between Waikane and Kahana Valleys will be acquired. The ditch trail continues tothe right and will become rough and overgrown quickly.
The way to the summit is to the left, HTMC cleared the route in the summer of 1999, but since few hikers use Waikane and because this area of the Koolau range receives a goodly dose of rain, the trail will overgrow quickly, with clidemia, thimbleberry, ginger, and uluhe the biggest culprits.
The path is cut into the massive wall of Kahana Valley and ascends in a half mile to a junction with the Koolau Summit Trail beneath a peak called Ka'aumakua. On the way up, some dangerous, precipitous sections will be encountered, with huge vertical plunges awaiting those not diligent about foot placement. Native plants abound along the trail, with species like kopiko, mamaki, olomea, and hoawa, among others, available for inspection. Wild pigs also use the trail, and signs of their presence, rooting and tracks, might be detected.
A rusted metal stake marks the junction with the summit trail. At that point. turn to inspect not only the marvelous climb just completed but the green maw of Kahana Valley and the pyramid mountain, Ohulehule, jutting out of its midst. The wind from the valley below accelerates up the mountainside, creating a rush of sound and cool conditions on even the most sunswept, humid days. Eat lunch at the junction while hanging your feet over the pali or head left to climb to follow the summit trail to reach the top of Kaaumakua or right to reach the terminus of the Schofield trail. About 20-30 minutes are needed for either of the two latter options.
Even with cautiousness applied on the precipitous sections, the return trip to the ditch tunnel will be faster. So will the walk out on the dirt road to the highway. It's a fascinating and challenging hike, one that I recommend to those looking for adventure.