Awesome Waterfalls, And a Swim Too
There are a few resources on the internet that will tell you about this hike. It is apparently published in a Maui hiking book as well, because several people asked us during the hike if we had heard about the hike through the book, which we hadn't. The important thing to note about successfully accomplishing this hike is to pay attention to the instructions for getting to the trailhead and getting through the bamboo forest. Otherwise, you'll likely get lost.
First things first, unless this is your planned last use of your hiking boots; you should wear footwear that can get wet and muddy. You're hiking along a stream with lots of mud and water. Whatever you wear on your feet, it will get wet and you'll likely fully submerge your footwear in mud. I wore Keene's. Teva's will work great as well. My Keene's cleaned up nicely after and hike and smell like Band-Aids again, just like they did the first time I pulled them out of the box. My hiking boots got muddy on a couple other Hawaii hikes and could not be cleaned and stiffened up. Also, use common sense along the stream. If it's raining hard, the stream will flood. If it's flooding it won't be safe.
Try to park as close to the trailhead coordinates as possible. That may be a tall order. If you have a handheld GPS, that will help you get to the trailhead from your car if you can't park close to the trailhead coordinates. The trailhead is not marked. From a road full of parked cars the area looks like solid vegetation. We saw numbers of people walking around looking for the trailhead. We parked within 20' of the trailhead. It is a hole in a barbed wire fence.
The hike is on land controlled by East Maui Irrigation (EMI) and there are no trespassing signs posted. However, it turns out that not only are land rights not enforced, the land is actually public (if the resources I researched are accurate). Nevertheless, the EMI presence is heard immediately on the hike and seen shortly thereafter as you cross an irrigation ditch that has rushing water in it, just 100 yards into the hike.
After passing through the hole in the fence you are immediately greeted by a tight, slippery trail filled with bamboo. The trail heads down hill a ways and reaches a steep slippery scramble down to the ditch crossing. After the ditch crossing there is a shorter but still steep and slippery scramble up the other side.
After scrambling up the other side there are two trails to choose from. Both trails join back up, but the trail to the left is the wider more well worn trail. The trail travels a short distance through a taller bamboo forest than the forest at the trailhead until the trail reaches the Na'Ili'Ili-Haele Stream. Here is where you'll make your first stream crossing.
The instructions here are important. I've read numerous accounts of people getting lost in the bamboo forest across the stream. After crossing the stream you will head up the embankment off to the left, into the bamboo. The stream will be to your left as you head upstream. The bamboo is very tall here and it is quite dark in the forest, particularly if it's cloudy. Nevertheless, you should still be able to keep track of the stream as you head up the trail. There are lots of trails that head off in different directions, all of which eventually dead end. However, if you simply keep an eye on the stream to your left, you won't get lost.
Eventually, you'll reach Falls #2. Falls #1 is downstream from the crossing and isn't as impressive as Falls #2, #3 and #4, so I didn't include it in the hike. You need to cross the creek here and head around the pool below Falls #2 on the left side of the pool. As you near the falls you will be greeted by a slippery rock wall that you have to climb. This is not a vertical wall and can be climbed fairly easily. There is a rope here as well, but you probably won't need it.
The trail continues for a short distance until you reach Falls #3, which is taller and more impressive looking than Falls #2. Stay to the left of the pool at the base of the waterfall and stay close to the water. The bamboo is very tight here, so staying close to the water gives you the clearest, although muddiest route to the waterfall. As you near the waterfall you are greeted by a wooden ladder tied to a rope that heads up a vertical rock face. The ladder is wobbly, but it is tied at the top and it won't fall. The ladder doesn't go all the way to the top of the wall, but from the top of the ladder, the remainder of the climb isn't too difficult.
From the top of Falls #3, the hike continues along a rock section of the stream for a fair distance. Keep in mind that if you go all the way to Falls #4, the round trip on this hike is only about 2.5 miles. So a "fair distance" is a relative term. Along this stretch there is lots of rock hopping and stream crossing. There are a couple of muddy sections, but for the most part, the hike is confined to the rocks and the stream. Eventually you'll reach a rocky slope that heads up along a steep rapid of the stream. At the top of this outcropping is a pool of water that I initially thought was the beginning of the swim. It isn't. You continue along the edge of this pool until you reach a cove. You climb up the rock wall and then are greeted with the swim.
The water is a pleasant 70+ degrees or so, but it is murky. A lot of people, including my wife, turn around here, rather than do the swim. However, you want to see Falls #4, don't you? In the water you go and swim upstream. I wore my Keene's on the swim and regretted it. They acted like little parachutes on my feet and really slowed and weighted me down. After swimming up the narrow channel, the pool rounds a bend to the left and opens up into a much wider pool. To the left is a hollowed out section in the rock wall with hanging ferns on its roof. About 2/3 of the way up the swim the little parachutes on my feet got the better of me and I needed to head over to the edge of the pool for a rest.
It turned out that I was close to the end anyway and continued on to a small 10 foot waterfall. This is where you exit the water and climb the rocks beside the waterfall. Even when wet, the rocks have hand and foot holds to allow you to safely climb to the top. At the top you travel a few yards up the stream and are greeted by the tallest and most beautiful waterfall of the hike - Falls #4. If you're as lucky as I was, you'll have the place all to yourself.
A word of warning, Maui has lots of mosquitoes and they're here on this hike as well. If you put bug repellant on at the beginning of the hike it all washed off during the swim. Consequently, The mosquitoes were all over me when I visited the waterfall. If you didn't bring more bug repellent with you on the swim, you may not want to stay at the falls very long, because the mosquitoes will start biting almost immediately.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.