Pu'u Ka'aumakua is a peak located in the Northern Ko'olau mountains of Oahu. It is one of the higher points in the northern part of the range and has an amazing view of the East shore and inland part of the island. Ka'aumakua is at the head of both the Kahana (N) and Waikane (E) Valleys. Easiest access to the peak is through the Waikane Valley but the summit is located just off of the Ko'olau Summit Trail so if you get to the KST from another trail you could make a trip up as well. This is a rounded, grassy peak, not a crumbly, rocky ridge like some mountains in Hawaii.
This route, I've read, is about 11 miles but I didn't bring my GPS to check, it took me and my dad 9 hours to complete, that's with no Hawaii hiking experience and at least an hour and a half trying to figure out where we were going. Start by Parking at the start of the Waikane Valley road off the Kamehameha Highway. We parked on the side of the highway.
beginning of the road
Start up the road passing a few houses and a church, the last house has dogs that will probably be out if it's early in the morning, they're nice enough, just walk through calmly and be friendly then go right through this gate right past the house.
go right here
Continue up the road and go down to the
right at this sign.
Pass a few turnoffs after this but keep going straight down the road, you should get to the military fence with these signs and cross the stream.
Keep following the outside of the fence all the way to the end and continue straight, then turn left at the fork and go past the sign with the chain across the road.
After this, walk the road for a while more, you have to cross a large landslide and a few drainages. At this point, the road starts to get overgrown and gives you a taste of what the rest of the trail is like. Eventually you get here where the first outlet tunnel is just up the road in a more straight direction (red arrow) along with some old concrete structures that are kind of cool, this is not the route, there is a different tunnel that you need to go to which is down, to the right and around the next corner (green arrow).
Continue on the road down and right
After Walking around the road for a short way you should first come to this black pipe, then this next spot with the tunnel just beyond that.
the tunnel is just behind that shack thing with the sign
Once you get here head straight up the ravine,
you're looking for the trail up on the right side
of the hill which isn't obvious at first, so walk up
a bit and look for the pink flags up the hill to the right.
There should be one on a small branch at your feet in
the bottom of the ravine marking where to start up the hill.
There is an old trail up on the left side of the hill but it just dead ends.
From there the trail should be obvious until you get to a streambed that may or may not have running water that you cross on some branches. the trail contours around this drainage and continues around the bend, however, there are trees fallen across it so it's not so obvious. At this point you may see a pink flag above the trail, don't follow it, I did and wasted almost an hour fighting my way up the hill and trying to find the next few. If you look across the ravine though you should see where there is a flat spot, the graded trail, just go under the trees and continue around the hill. Sorry, I forgot to get a picture of this one. Hike to the saddle which may be easy to miss but is marked by your first big views of the valleys. Switchback left up the narrow trail to continue to Pu'u Ka'aumakua, going straight takes you to Pu'u Ohulehule.
From here the trail is slippery, overgrown, and narrow all the way to the junction with the KST, which isn't any better, where you again switchback left toward the summit. The junction is marked by a tall stake with a flag and some pattern duct tape on it. Once on the KST follow as it crosses to the leeward side of the crest then a while later back up to another saddle however you may not want to go that far. If you get to the second saddle Ka'aumakua is on your left (North) if you're facing the ocean. There is supposed to be a trail leading to the summit but I never saw one so we followed the ridge mostly straight to the summit, which was really horrible, we never touched the ground almost the whole way because the vegetation is so thick. I would recommend hopping off the trail just East of the peak at a spot just after the trail goes left around a bend and then goes across a nice grassy area before traversing right again. Get off at the tip of this < shape and the peak is just West of you, the coordinates are approximately (21.5011°, -157.8986°). If you can look South and see the trail going up the face of another mountain back the other way straight across from you then you're in the right place. From here either go straight up the face, or head north to a saddle an take the ridge West to the summit. The summit is about 30 minutes from the KST junction.
I'm not really sure If you need any special permissions to go through the area like in some other parts of the island. I've read that the route crosses private property but I can't see where that would be. The only thing I can think of is just don't go into the fenced off area. You might see some military personnel but they probably won't have a problem if you tell them that you're just hiking and where you're going.
What to Bring
Make sure to have enough water for the day, shoes with good tread, your camera, long pants as there is a lot of unfriendly vegetation and the directions on paper. A GPS would be especially helpful in determining which is the correct peak and to figure out if you're on course if you get socked in towards the top.
When to Climb
All year is fine but I think summer is generally best for Hawaii because there is less rain but that being said it still rains all the time in the mountains and we were wet pretty much all day in August after it rained pretty good early on but then let off and was all clear by 1:00. We were moving so we were warm enough and didn't mind the wet much. I wouldn't want to be hiking this narrow, exposed trail in heavy wind and rain though.
The views from the top are beautiful if it's not socked in. If it were bad weather all day I don't think the hike would be worth it. This is truly an adventure if the trail hasn't been maintained and you will most likely get your butt kicked by nature. The trail is pretty technical especially when wet, which is basically always. When you do slip off the trail, it will probably happen a few times, it's pretty easy to recover because of all the vegetation to grab onto. That being said, there are some places where it's just a dang steep fall and you do not want to slip or it would not be pretty. Not appropriate for inexperienced hikers.