Hiking the Puʻu Kōnāhuanui Ridge Trail (Tantalus to K1) on Oʻahu, Hawaiʻi
Distance: 8.2 miles / 13.2 km
There’s a saying that Oʻahu hikers use, which is 'all trails on Tantalus lead to K1,' more formally known as Puʻu Kōnāhuanui.
That being said, the Puʻu Kōnāhuanui Trail, by way of Tantalus, is best climbed from either the Puʻu ʻŌhiʻa or Kalāwahine Trail. I say this because either option is easily the most straightforward route up the highest peak in the Koʻolaus and the third-highest on Oʻahu, standing at 3,150 ft. (960 m) above the Honolulu skyline to the south and Maunawili to the east.
However, just because it’s the tallest peak in the Koʻolaus does not mean that it’s the hardest hike. By comparison, the neighboring Puʻu Lanihuli is considerably more challenging to reach a shorter summit.
In any case, there are many different ways to reach the summit of Puʻu Kōnāhuanui, including multiple routes from Nuʻuanu, multiple routes from Mānoa Valley, and multiple different routes from Tantalus, but in this post, I chose to begin from one of the two most practical routes on Tantalus: the Puʻu ʻŌhiʻa Trailhead.
Puʻu ʻŌhiʻa Trailhead Parking
Parking for the Puʻu ʻŌhiʻa Trailhead is located directly off Tantalus-Round Top Drive where the road crests at its highest point from either direction before heading back down again.
Out of caution, consider the Puʻu ʻŌhiʻa Trailhead to be a high-crime area for petty theft, meaning you should never leave visible bags or anything valuable in your car.
Google Maps Directions: Puʻu ʻŌhiʻa Trailhead
Hiking the Puʻu Kōnāhuanui Trail
On Tantalus, the general rule of thumb is that all trails lead to K1. However, the most practical routes to Puʻu Kōnāhuanui are either from the Puʻu ʻŌhiʻa or Kalāwahine Trailhead, which both begin within a mile of each other off Tantalus-Round Top Drive.
That being said, you’ll have to decide which sounds like the better option to you. What I mean is that the Puʻu ʻŌhiʻa Trailhead has a better parking area than Kalāwahine, but the trail climbs up and down Puʻu ʻŌhiʻa, which is somewhat annoying—especially on the return hike.
On the contrary, the Kalāwahine Trail is a bit flatter and slightly shorter, but the parking situation can be more challenging, as there are fewer spaces to park off the side of the narrow road.
In any case, the Puʻu ʻŌhiʻa Trail to the Mānoa Cliff Trail junction is 0.8 miles (1.3 km), followed by another 0.5 miles (0.8 km) to get to the junction where Kalāwahine meets up with the Pauoa Flats Trail.
If this sounds confusing, I encourage you to use the map below or check out my separate post to see how all the Tantalus Trails wind together to make this larger network.
Read My Separate Post: Tantalus Loop Trail
Right from the start, the Puʻu ʻŌhiʻa Trail immediately begins climbing.
When you come to this or any other splits off of the main trail, don’t follow them.
The Puʻu ʻŌhiʻa Trail should continually climb uphill until Telephone Road, shown below.
Telephone Road
After just 0.4 miles (0.6 km), the Puʻu ʻŌhiʻa Trail joins with Telephone Road.
Go right to continue toward the Pauoa Flats Bench.
At this point, you should get your first view of Kōnāhuanui before descending back down into the forest.
The next time the peak is visible won’t be until the contour trail a few miles up the trail.
Mānoa Cliff Restoration Area
The next section across Tantalus passes through the Mānoa Cliff Restoration Area.
Essentially, Mānoa Cliff is a heavily-managed restoration site focuses on native species restoration and biodiversity, while keeping non-native ungulates out.
Therefore, please be sure to close the ungulate-exclusion fence after passing through.
Puʻu ʻŌhiʻa-Mānoa Cliff Junction
When the Puʻu ʻŌhiʻa Trail meets up with the Mānoa Cliff Trail, go left to continue toward the Pauoa Flats Bench.
On a different note, this short stretch to the next gate is my favorite stretch of trails on Tantalus because of all of the different native species you can find in such a small area.
Mānoa Cliff-Pauoa Flats Junction
When the Mānoa Cliff Restoration area comes to an end, go straight to begin the Pauoa Flats Trail.
Pauoa Flats is the last trail on Tantalus before continuing further up the true Puʻu Kōnāhuanui Ridge Trail.
Pauoa Flats-Kalāwahine Junction
This is the exact trail junction where the alternative Kalāwahine Trail meets up with Pauoa Flats, essentially cutting out everything mentioned above on this separate access trail.
Go straight (right) to continue to the Pauoa Flats Bench.
Pauoa Flats-Nuʻuanu Junction
Next, the Pauoa Flats Trail will pass by the Nuʻuanu Trail, which is more or less a connector trail down to Nuʻuanu Valley and the Judd Trail.
Continue straight (right) to remain on the Pauoa Flats Trail.
Read My Separate Posts: Nuʻuanu Trail / Judd Trail
Pauoa Flats-ʻAihualama Junction
Shortly after the Nuʻuanu junction, the Pauoa Flats Trail will again pass by another connector trail, known as the ʻAihualama Trail.
Essentially, ʻAihualama connects the very end of the Mānoa Falls Trail with Tantalus by way of the ʻAihualama Trail.
Read My Separate Posts: ʻAihualama Trail / Mānoa Falls Trail
Pauoa Flats Bench
The Pauoa Flats Bench is the end of the maintained trails on Tantalus.
From here, Puʻu Kōnāhuanui Trail continues straight past the bench, which is where the trail will noticeably become less traveled.
That being said, I recommend hiking pants for the remaining sections, as the overgrowth will only become worse and worse the further you hike from Tantalus.
The pants below are my recommendations that hold up the best with the overgrowth here in Hawaiʻi, but with any hiking pants that need to be durable, make sure that they are at or near 100% nylon. This is really the most important factor!
Puʻu Kōnāhuanui Ridge-Contour Junction
After just 0.25 miles (0.4 km) from the Pauoa Flats Bench, the Puʻu Kōnāhuanui Ridge Trail comes to a bit of a vague trail junction.
In short, there’s a ridge trail that continues straight and follows the crest of the ridgeline, and a contour trail that makes this hard switchback. However, both trails lead to the same place further up the mountain.
That being said, I almost exclusively take the contour trail because it’s much easier.
By this, I mean that there’s no unnecessary up and down on the contour trail as opposed to the ridge trail. The contour trail only gains about 300 ft. (91 m) over the course of 0.9 miles (1.4 km) to get to the same exact spot as the ridge trail, which does much more unnecessary climbing and descending to reach the same spot.
Upper Puʻu Kōnāhuanui Ridge-Contour Junction
This is where the contour trail and the ridge trail come back together for the rest of the hike to Kōnāhuanui.
Over the next 0.8 miles (1.3 km), the Puʻu Kōnāhuanui Trail gains about 1,000 ft. (305 m) to the summit of K2—the lower of the two summits—by about 100 ft. (30.5 m).
If you look closely, you can see one of Hawaiʻi’s endemic Damselflies.
Puʻu Kōnāhuanui II (K2)
The photo below is the summit of K2, and just prior to this point, the Koʻolau Summit Trail (KST) meets up with the Puʻu Kōnāhuanui Trail from the ridgeline across Mānoa.
From K2 to K1, the there’s only about 0.4 miles (0.6 km) along the KST to reach K1, the higher of both summits on Kōnāhuanui. However, the one annoying part is that the ridgeline drops about 100 ft. (30.5 km) off of K2 to cross over to K1.
This is one of my favorite photos I’ve ever taken anywhere across the summit trail!
Puʻu Kōnāhuanui (K1)
After the short 0.4 miles (0.6 km) traverse from K2, the Puʻu Kōnāhuanui Trail ends at the 3,150 ft. (960 m) peak—the highest summit in the Koʻolau Mountains.
On a clear day, you can see expansive views in all directions, including the Waiʻanae Mountains and Mt. Kaʻala to the west, Puʻu Lanihuli to the north, Mt. Olomana to the east, and other notable hikes, like Waʻahila Ridge to the south.
Furthermore, many in the hiking community are aware that the trail doesn’t necessary end at the summit of Puʻu Kōnāhuanui, but I caution against proceeding in any direction off the summit, other than the same ridge trail to get here.
I say this because all hikes, including Lulumahu Ridge to Lulumahu Falls, the KST to the Pali Notches, Piliwale, and the KST across Mānoa are all significantly more difficult and more dangerous.
Native Plants on the Kōnāhuanui Trail
Being that Puʻu Kōnāhuanui is the highest peak in the Koʻolau Mountains, the entire trail has a ton of native diversity, which is surprising for its relative close proximity to Honolulu.
Some of these species are so rare that they only exist on Kōnāhuanui and nowhere else on earth; I mention this to encourage responsibility in this sensitive environment.
Some of the native plants that you can find on the trail include, but are not limited to, Koa, Kokiʻo Keʻokeʻo, ʻŌhiʻa, ʻAkolea, Lapalapa, Alani, Kōlea, ʻAhakea, Kōpiko, Naupaka, and Olonā, to truly only name a few. The summit area is by far the best area in the southern Koʻolaus to see the fan favorite of the two Lapalapa species.
If you would like to know more about these and tons of other native Hawaiian plants from across the islands, I encourage you to check out my separate post linked below.
Read My Separate Post: Native Hawaiian Plant Guide
