Hiking the Judd Trail & Jackass Ginger Pool on Oʻahu, Hawaiʻi
Distance: 1.2 miles / 1.9 km
The Judd Trail, also called the Judd Loop Trail, in Nuʻuanu Valley on Oʻahu, is a short 1.0-mile (1.6 km) loop at the base of the Nuʻuanu Trail and the extensive Tantalus Trail network that leads hikers through a beautiful, towering Cook Pine forest along the Nuʻuanu Stream.
That said, the Judd Trail is most famously known for a fun natural waterfall and swimming hole in the stream, known as the Jackass Ginger Pool, and the best part is that the pool is only a short hike from the trailhead!
All that to say, whether you’re looking for a fairly easy hike, a great but muddy Oʻahu trail run, or a fun place to swim, the Judd Trail really has it all—especially if you extend the hike up to the Pauoa Flats Bench via the Nuʻuanu Trail up on Tantalus!
Judd Trailhead Parking
Parking for the Judd Trail is located on the side of Nuʻuanu Pali Drive, just up the hill from the infamous Morgan’s Corner.
Out of caution, consider the Judd Trailhead to be a high-crime area for petty theft, meaning you should never leave visible bags or anything valuable in your car.
To add to this warning, never park at this trailhead with an expired registration or safety check. The Honolulu Police Department and towing companies target this area for cars that they can legally tow if one of these two things is expired.
Google Maps Directions: Judd Trailhead
Hiking the Judd Trail
The Judd/ Jackass Ginger Pool Trail is a relatively flat hike, with one stream crossing that can be challenging if the water is running high.
Shortly after the trailhead, the Judd Trail appears to split, but to stay on the official route, go right to continue across the Nuʻuanu Stream.
Nuʻuanu Stream
After just 0.1 miles (0.2 km), the Judd Trail crosses the Nuʻuanu Stream.
There is usually a way to cross on the rocks without getting your shoes wet, but this may not be the case if the stream is running high—typically during the wetter winter months.
Judd Loop Trail
On the far side of the stream, there’s either the option to go left (straight) around the upper side of the Judd Loop, or right to hike to the Jackass Ginger Pool on the fastest route, about 0.25 miles (0.4 km) away.
If you were planning to hike the full Judd Loop Trail, I recommend going left on the upper trail first because the upper half of the trail is slightly longer.
This way, when you reach Jackass Ginger, it ends up being a great spot to stop and cool down before completing the hike, not to mention that the Judd Trail can be very muddy, which makes the Jackass Ginger Pool a convenient place to clean off, since most of the hike is already over by that point.
Judd-Makuku Ridge Junction
When the Judd Trail passes this obvious trail on the left-hand side, go straight to continue on the Judd Loop toward the Nuʻuanu Trail junction, as this is the split for the very steep Makuku Ridge Trail, which intersects the Nuʻuanu Trail higher on Tantalus.
This bend in the Judd Trail is easily the most confusing part of the upper Judd Loop because there isn’t one clear path when coming from either direction.
That said, don’t hike uphill. Instead, follow the path to the left around the lower part of the hill to find where the Judd Trail continues on the other side.
After the open section shown above, the Judd Trail becomes much more straightforward for the rest of the hike to the Nuʻuanu junction just a short distance ahead.
Judd-Nuʻuanu Junction
After 0.5 miles (0.8 km), the Judd Trail finally meets the Nuʻuanu Trail, just before the Judd Loop drops down to the lower half that passes by Jackass Ginger Pool.
That said, the Nuʻuanu Trail is more or less a connector hike with the much larger Tantalus Trail network farther up the mountain.
All this to say, I personally think that the Nuʻuanu Trail makes for a great standalone day hike, with amazing views once you get to the upper sections of the trail. However, the Nuʻuanu Trail makes for an even better connector when combined with longer day hikes, such as Lulumahu Ridge or the Pali Notches to Puʻu Kōnāhuanui on the Koʻolau Summit Trail (KST), as this is how the best loops can be created!
Read My Separate Post: Nuʻuanu Trail
After the Nuʻuanu Trail junction, the Judd Trail continues on the upper portions of the loop for another 0.1 miles (0.2 km), where it will then start descending to the lower half along the Nuʻuanu Stream.
This is where the Judd Trail starts descending the southernmost side of the loop.
If you are interested in running the Judd Trail or even the Nuʻuanu Trail up to Tantalus, I recommend considering a trail-running shoe that can handle Hawaiʻi’s muddy, slippery trails—especially those that make up the Tantalus Trail network!
This is one of a few sections that tend to be the muddiest on the Judd Loop Trail, even if it has been a few days since the most recent rain.
This is where the Judd Trail turns the corner to begin traversing the lower, northernmost half of the loop along the Nuʻuanu Stream.
Hau trees are one of the very few native Hawaiian plants along the entire Judd Loop Trail.
Since the Judd Trail can be so muddy along the lower half of the loop, some hikers may want to carry trekking poles, which can certainly be useful for countless other day hikes across Oʻahu.
Nuʻuanu-Jackass Ginger Pool (Kahuailanawai) Juction
With about 0.25 miles (0.4 km) left before the Judd Trail returns to the beginning of the loop, the trail passes the junction for the Jackass Ginger Pool on the left-hand side.
From here, hikers either have the option to follow the steep trail off the main loop to the little swimming hole and waterfall, about 40 ft. (12 m) below, or to go straight to return to the Judd Trailhead and skip the pool.
This is the very short, steep descent down to the Jackass Ginger Pool.
Jackass Ginger Pool (Kahuailanawai)
Kahuailanawai, more commonly known as the Jackass Ginger Pool, is a deep pool in the Nuʻuanu Stream that is popular among both residents and visitors alike for hanging out and jumping in—especially in the late evening, when the golden light brings out the best of the forest and the waterfall!
That said, I think it’s important to mention that Hawaiʻi streams are not always the cleanest, on account of a waterborne bacteria known as Leptospirosis.
I say this because if you have any open cuts, it’s best to avoid swimming in the Jackass Ginger Pool—or other popular waterfalls for that matter—like Maunawili Falls.
After the Jackass Ginger Pool, there is only 0.25 miles (0.4 km) left to return to the beginning of the loop, and 0.1 miles (0.2 km) after that to reach the Judd Trailhead.
At the bottom of the hill shown above, the Judd Trail remains mostly flat for the rest of the hike back to the beginning of the loop.
Judd Loop Junction
This is where the Judd Trail completes the 1.0-mile (1.6 km) loop, adjacent to the first Nuʻuanu Stream crossing shown at the beginning of this article.
From here, go left to cross Nuʻuanu Stream and return to the Judd Trailhead off Nuʻuanu Pali Drive.
Native Plants on the Judd Trail
The Judd Trail is a very low-elevation hike by Hawaiʻi standards, meaning the trail is mostly dominated by non-native invasive species.
This is why the most obvious native species hikers are likely to find are a few Hau trees scattered throughout.
If you would like to learn more about Hau and many 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
