Blue Hole

Page Type Page Type: Route
Location Lat/Lon: 22.06490°N / 159.4917°W
Additional Information Route Type: Muddy trail, degenerating into jungle
Additional Information Time Required: A long day
Additional Information Difficulty: Easy to Extremely Strenous hike, depending on distance
Sign the Climber's Log


The Blue Hole refers to the deep canyon found on the east side of Mount Waialeale. Fantastic walls rise over 3,000ft around it, nearly encircling it on three sides. This dramatic scene, a backdrop for the movie Jurassic Park, was created as the result of errosion, not as the cauldera of an ancient volcano as popularly mistaken (Mt. Waialeale's cauldera is a barely recognizable depression a few miles northwest of the summit highpoint, buried deep in the Alakai Swamp). There is no lake at the center or anywhere within the Blue Hole as sometimes believed. It is likely the name comes from the dark green vegetation that covers the floor and even the vertical walls, producing a bluegreen tint when viewed from a helicopter under the usually heavy cloud cover.

A hike into the Blue Hole is a grand Kauaian adventure involving stream travel and jungle trekking along a thinly flagged, unmaintained trail. The total distance from the trailhead is less than 3mi, but this can take you up to 9hrs to reach, depending on your speed of travel and route-finding skills. Your reward upon reaching the inner sanctum is a close-up look at the most amazing waterfalls in all the islands - streams of water dropping over 1,000ft in height, over vertical, verdant walls that have a very ancient and mystical presence. There is also a large cavern (possibly another source of the feature's name) at the very center where the floor of the canyon meets two vertical walls. The inside of this cavern is some 150 feet off the floor, guarded by wet, mossy walls that appear unclimbable by any means. Perhaps you could be the first?

Though a generally wild adventure, you will not feel a sense of aloneness with the near-constant drone of helicopters into this area. This is one of the highlights of every Kauai helicopter tour, so just accept that they'll be coming by every 5 minutes starting after about 8a, sometimes one right after another.

This page was originally created by another member (no longer active) who got many of the details wrong, but nonetheless inspired others to take up this fun adventure. I left the original summary at the end for some mild amusement.


The eastern base of Waialeale is reached by a paved highway from Wailua, which degenerates into a rugged and muddy dirt road where 4WD is recommended.

From Wailua, take State Route 580 (Kaumoo Road) west. At the beginning, the highway is a well-used tourist route which passes an often photographed Opaekaa Falls and a scenic overlook into the Wailua river valley. The road then passes through some residential areas and then continues upward into increasing thick jungles. The road is paves as far as the Keahau Arboretum approximately 5.5 miles from the start. Here the road fords a stream (about 4-6 inches -- any car can handle). The Arboretum is a semi-wild park that is popular with families. You can park here and stroll through the area.

Beyond the Arboretum, the road becomes very rugged dirt. A sign says "4WD Only Beyond This Point," and we strongly recommend at least a high-clearance vehicle like a pickup. (Although sedans have made it, this is risky. Past the Arboretum, the road climbs a hill to reach a hunter check station (some notices posted on a board), the TH for the Kuilua Ridge Trail and a small side road on the right - the start of the Powerline Trail. The main road then continues downhill to the left and fords another stream. (The ford is lined with concrete and safe for
any vehicle.) Continue on this road, eventually following some power lines until you come to a "T" intersection, where you should turn right. Continue on this travelled road for a couple of miles. When the road forks at various places, stay on the straightest and most travelled route. Eventually, you will reach a gate. If the gate is locked, you will have to park here and continue walking along the road past the gate. If the gate is open, you can drive about a mile further to a dam, where the road ends. This is the trailhead. All of this is described with an excellent map in the book, Ultimate Kauai Guidebook under a section describing the "Jungle Hike" (which is a trail that follows an irrigation ditch starting near the same dam). This book is the best available on Kauai and is indispensible - enough said - just buy the book.

Route Description

The overall aim of this route is to follow the river (a fork of the Wailua River) as far as you can go toward the base of Waialeale.

At the dam, hop across rocks or wade across the river to the right bank. If you're committed to reach the Blue Hole you are certain to have soaked boots and feet upon your return. Consider this while you prance around the stream's edge for the first few hours trying to stay dry - you could save yourself considerable effort if you just start out by getting them wet. Follow the north side of the streambed, looking for paths worn in the nearby jungle brush where travel along the stream itself is barred. Hunters use this area regularly and there are numerous trails heading off away from the stream - save yourself more trouble and avoid these minimally flagged diversions unless you're looking for, well, a diversion.

After a bit less than 2 miles, you will come to an obvious waterfall, the only one encountered since the dam. This is a good place for a break and a cold swim in the large pool (this site claims this pool as the namesake for the Blue Hole). Three streams come together at this point to form the waterfalls and pool. The stream on your left (no waterfall) is the main stream coming from the inner sanctum. Unfortunately you can't follow up this creekbed as impassable cascades are encountered within 50 yards (go ahead and try, the reasons will quickly become obvious). The stream on the right (one of the waterfalls) can be followed to its end about a quarter mile further on where it runs up against a vertical wall and one of those impressive waterfalls I already told you about - this is a good option if you haven't got much time left and want to get a taste of what it looks like in the inner sanctum. The middle stream (and the other waterfall) is your key to further progress.

To surmount the waterfall, you need to take a route that goes up the left side of the middle stream, starting between the left and middle streams (you have to cross the left stream). The route is (barely) visible from the pool, but is unflagged and therefore non-obvious. The non-flagging appears to be designed to discourage the uninitiated. Once atop the waterfall, flagging begins to appear, following on the left side of the middle stream. At times you must follow the stream where no trail exists on the side, and it is here that it will become unavoidable to walk in the stream itself in places. Key flagged sections will take you past impassable sections of stream and a deeply gouged canyon. You are basically following this middle stream west and then south until it ends. Climb the south bank of this drainage where possible - some flags should be present here. Follow these until you crest the divide between this drainage and the next one to the south. Follow the flagging as it takes you steeply down to a small creek, then follow it west upstream (no flags, but easy to navigate in the streambed). Where this ends in a dry streambed heading south, flags reappear to take you up to the divide between this middle drainage and the inner sanctum. At the crest the flagging ends and you can view the gigantic cave at the end of the Blue Hole. This is the inner sanctum.

There is no flagging (at least when I was there) past this point, and at first this last 1/3 mile looks fairly daunting. But notice that the vegetation near the western wall is stunted. Old rockfall underlies this greenery, and the poor soil means less plant growth and easier navigation. Head for the west wall and follow it to the inner cave. You can climb into the cave beyond the vertical to get out of the water drip line, but it appears unclimbable past a small cairn built at the highest reachable spot.

A cautionary note: the USGS 7.5' topo does not accurately represent the Blue Hole. It shows only 2 drainages near the west wall where there are three, and it appears the creek originates from a notch east of Kawaikini and down a 45-degree canyon on the south end of the inner sanctum. In fact, the walls are near vertical on the south side.

Return via the same route.

Essential Gear

You will get wet and muddy along this route. Sturdy boots, long sleeve pants and shirt are highly advised. It will probably rain on you sometime during the journey, but the temperature is usually pleasant.

Original Summary

The Blue Hole is a small lake at the base of the cauldera of Waialeale. Your maintainer has tried to reach it but failed. The setting has to be very dramatic, surrounded on three sides by giant green cliffs draped with streaming waterfalls. Even if you don't reach the lake, scenery is spectacular -- a scene out of Jurassic Park, quite literally.

We know that the Blue Hole exists and is reachable, because it we featured in a Travel Channel documentary, with a title something like, "The World's Top Ten Adventure Destinations." In the short segment, which lasted only 3-5 minutes, a group of hikers took all day to reach the lake, swam in it briefly, then hurried back. Camping, it was said, was not permitted, so the trip could only be made in one very long and strenuous day. The water was supposedly very cold, presumably because it had just fallen from the summit at over 5000 feet.

We have never seen any aerial photos of the Blue Hole, but here is a good photo of the caldera, some helicopter shots of the vicinity and an artist's idealized image.

Several tour companies offer van tours to the "Blue Hole," but this could only be to the road-accessible trailhead far below, not the true inner core of the caldera.

In the documentary, the actual lake seemed a bit of a disappointment -- not obviously scenic on TV. The main pleasure is probably the wonderful scenery along the way, so the route can be as hard or easy as you want to make it. Simply to drive part way up the access road and walk around a bit may be enough for many visitors.

There is probably no way to reach the summit directly from the Blue Hole, even for the most daring rockclimber. The cliffs are nearly vertical and almost completely moss-covered and waterlogged.

Additions and CorrectionsPost an Addition or Correction

Viewing: 1-5 of 5

glowingrock - Oct 16, 2003 11:48 am - Hasn't voted

Route Comment

This road was recently improved. We drove it in August of 2003 in a Dodge Neon without any problems. It was still a bit rough for the last couple of miles but it was obvious that they were still planning on improving that section as well.


glowingrock - Oct 16, 2003 11:56 am - Hasn't voted

Route Comment

Above the falls, the boulders seemed to double in size and the terrain got steeper. This, of course, meant more waterfalls to climb around. One trail around a waterfall was a 12 inch wide shelf with a steep drop-off on one side down to the river 30 feet below.

As we pushed deeper into the crater, the 5000 ft. vibrant green moss covered walls closed in on all side. As expected, it rained on us off and on most the day. Waterfalls dropped from the top of the crater in every direction. Other less ambitious people wanted to share the fruits of our toil. My wife counted 65 helicopters that buzzed overhead during our 12 ½ hour slog. As we marched further, it was apparent no one had been as far into the crater as we were in a long time. Not including the helicopters, we never saw a single person on the entire hike. The rare pink ribbon marking the route was our only reminder of prior explorers.

At around 2 pm, our hopes of reaching the Blue Hole faded. Time was the enemy. As we reached the end of the caldera, seven hours into the hike, we realized that to have any chance of getting out before dark, we had to retreat immediately. So on the spine of a steep ridge covered in waist high bushes and ferns (see photos which I posted), I snapped a few photos of one of the most incredible places in the world and we headed back.

On the way out, we somehow lost the route and ended up bushwhacking up a steep slope covered in nasty vegetation that was tall, thick, and sharp. The skin on our legs, arms, and hands was slashed and cut. We traveled at a snail’s pace. The bush was so thick it got dark inside. On one occasion, either out of necessity or frustration, I launch my body forward just to get through. We fell to the muddy ground time and time again. Eventually we battled our way back down to the river. After sunset, navigation became more difficult. Another dark and anxious hour passed before we emerged from the jungle. I’ve never been so happy to see a rental car before.

During our journey that day, we got lost more times than I can count. Everything we brought got completely soaked. Our bodies were cut, bruised, battered and we were filthy, hungry, and exhausted. It was one of the best days of my life!


mpbro - Oct 16, 2003 3:26 pm - Hasn't voted

Route Comment

Great story! Hopefully you'll add it as a trip report (click "TRIP REPORTS" link). You can integrate the photos you've submitted and basically add any HTML you like.


glowingrock - Oct 16, 2003 11:58 am - Hasn't voted

Route Comment

Due to the extensive hiking in the rock covered river, Leki (or some other type of hiking sticks) are very helpful.


benthegrate - May 7, 2009 12:11 am - Hasn't voted

Route Update

Due to the publication of the first part of this route up to the 2-stream waterfall in the most popular guide to Kauai, the first 2 miles this route are becoming "highly" trafficked. (That term is certainly relative, as Kauai sees a fraction of the tourists of other islands.) However, probably because of this influx of comparative amateurs, all flagging that is described in this route has been REMOVED. Consequently, if you want to attempt to get all the way to the back wall, you've got to have killer instinct, a rapid pace, and an early start. The trails are misleading, there is no flagging, and there are more and more people tearing up the hints of trail that do exist in an attempt to reach the crater. It is MUCH farther than this entry will lead you to believe. And since there is no longer any flagging to guide you to the correct places once you leave the middle stream, the chance of error is extremely high. I recommend planning on a hammock/rain fly bivouac (which is, perhaps, illegal?) if you intend to make it all the way there and back. (There is no place clear enough for a tent back in there.) Condition of the road in May 2009 was very poor...high clearance required beyond the T-junction 2 miles past the Arboretum. We had very dry conditions for 3 day preceding our trip, but the road had massive potholes and deep mud.

Viewing: 1-5 of 5



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