This somewhat rough path, popular among hunters, drops down from the western rim of Waimea Canyon more than 2,000 feet to reach the Waimea River at the bottom. It’s a workout, no question—especially the return leg climbing back upslope. But it’s also sure to be a few hours of your Kauai visit you won’t soon forget: a taste of backcountry adventure without getting too terribly remote.
The Kukui Trail is a strenuous, five-mile round-trip undertaking involving about 2,240 feet of elevation gain. It begins at the Iliau Nature Loop Trail, below a roughly 3,000-foot knob overlooking the canyon called Kukui. The knob and the trail are both named for the kukui nut tree, common on the Waimea Canyon sidewalls.
This tree, also known as the candlenut or the candleberry, was widely spread around throughout the Indo-Pacific from some unknown origin by seafaring peoples in ancient times.
The Kukui Trail wastes no time beginning its descent. The first part of the trail proceeds northeast down a spur ridge. Then it jogs north down a slope, then northeast to reach the canyon floor.
Along the plunging way, you’ll nab some nice views of the broad, multicolored “Grand Canyon of the Pacific,” including some of its tall waterfalls. You’ll also negotiate a reddish, somewhat precarious slope informally called “Red Hill.” This and some other sections of the Kukui Trail can be treacherous in wet conditions, when (like many Kauai paths) the tread becomes muddy indeed. But even in dry weather watch your footing carefully.
A campsite run by the Hawaii Division of Forestry & Wildlife, Wiliwili Camp, sits along the Waimea River at the trail’s turnaround point. You can bed down here with the proper permit. Otherwise, take a breather, maybe a dip in the Waimea River pools, before tackling the tough climb back up to the rim.
Expect sun exposure on much of the Kukui Trail, though significant portions pass under forest canopy (including kukui boughs). Besides stepping carefully, the main challenge is drinking enough water. It’s a great idea to bring along a filter or purifier so you can refill at the Waimea River, the Koaie Stream, or possibly other sources: That way you’re sure you’ll be able to stay hydrated, and you don’t have to haul large amounts of water along the way.
You’ll be huffing and puffing a bit once you get back to the trailhead, and you may well feel this hike in your calves over the next day or two. But the thrill of hiking from rim to river in the extraordinary Waimea Canyon makes it all worth it!
If you arrange a shuttle, it’s possible to skip the climb back up the Kukui Trail. You can follow a track down the Waimea River from Wiliwili Camp out the canyon mouth to Waimea. This is about an eight-mile hike and involves multiple river crossings, though, so be prepared.