What to Know About the Kukui Trail in Kauaʻi’s Waimea Canyon

Only one hiking trail takes you down to the bottom, where a gently flowing river serves as a refreshing swimming hole at the halfway point.

Mark Twain dubbed it The Grand Canyon of the Pacific. Measuring 10 miles wide and 2,000 feet deep, Kauai’s Waimea Canyon may be a miniature version of her Arizona sister, but with waterfalls and hues of green, she’s arguably prettier. Only one hiking trail takes you down to the bottom, where a gently flowing river serves as a refreshing swimming hole at the halfway point. The Kukui Trail is a difficult, narrow switchback offering hikers dramatic panoramic views of distant waterfalls trickling down the walls of the ruddy gorge. These spectacular vistas make it worth the sweat, but be warned: Once you reach the canyon floor, it’s a brutal, glute-burning climb back up to the top.

The Kukui Trail can be a bit tricky to find. The trailhead is hidden about three quarters of a mile past the 8 mile marker on Highway 550, the 18-mile road leading up to the canyon. The start of the trail overlaps with Iliau Nature Loop, a flat path that travels a third of a mile along the canyon’s rim before it winds back to the main road. At the rim, the Kukui Trail keeps going down and in for another 2.5 miles. If you go, budget about four hours for the hike — and bring plenty of water.

The Kukui Trail is like a steep set of stairs. It’s all downhill into the gorge and all uphill on the trek back up. About half the trail is unshaded — a hat and sunscreen make for wise hiking companions — while other sections meander through the kukui forest that lends the trail its name. The kukui tree was designated the official state tree of Hawaii in 1959. Its green nuts are popularly pressed for their oil, which has natural moisturizing properties that make it a common ingredient in skincare products. The tree is abundant across the slopes of the canyon.

Waimea Canyon was carved out of the red dirt by a raging Waimea River, swollen with rainfall collected from Mount Waialeale, which is widely considered one of the wettest spots on earth. Waimea is the Hawaiian word for “reddish water,” a nod to the canyon’s formation. Today the river that cuts across the canyon is slow and placid — a perfect place to cool down before commencing the strenuous uphill march out of the valley.

The trail is commonly used by hunters as well as paniolo, which is the term for a Hawaiian cowboy. As you climb, be on the lookout for goats and horses on the loose. The trail is often slippery, particularly after periods of heavy rain. But due to its steep grade — the trail makes a 2,000-foot elevation drop — it can also be hazardous when dry. The red soil will sometimes literally crumble under your feet, which can set you into a dangerous slide. Sturdy hiking shoes and a walking stick are highly recommended if you set out to complete this hike.