Nāpau Trail

Nāpau Trail is a 12.4-mile out-and-back from the Maunaulu parking area to the Nāpau Crater overlook on Kīlauea’s East Rift. It crosses the Maunaulu lava fields, skirts Makāopuhi Crater, then enters tree-fern rainforest before ending above Nāpau, with Puʻu ʻŌʻō across the crater. It’s a rewarding choice if you want a long, varied walk and are comfortable on rough lava. Plan on about seven hours with stops. The listed 6.2 miles is one way; you walk back over the same ground.

Sign the trail register, walk about 100 feet on pavement, then turn left onto the Puʻu Huluhulu trail. Numbered interpretive stops lead to the Nāpau junction at about a mile. From there the route heads east across open lava, reaches Makāopuhi at roughly mile 2.2, and eventually trades the exposed flow for thicker forest. At the far end, the route reaches a steep overlook above Nāpau Crater. The walk is not a summit climb, but twelve miles of uneven ground makes it a serious day out.

Maunaulu means “growing mountain.” Its eruptions from 1969 to 1974 left the lava rivers, channels, tree molds and pit craters along the route. The trail follows part of the East Rift Zone, where magma once moved underground from Kīlauea’s summit toward Puʻu ʻŌʻō. The crater approach now crosses a younger lava flow; stay on the marked line rather than trying to find a smoother shortcut.

Makāopuhi is where the route’s open volcanic ground gives way to dense rainforest. The crater erupted in 1922, 1965 and 1972, partly filling its west side. Beyond its rim, hāpuʻu tree ferns close in overhead, and the old pulu factory ruins sit along the trail. Look for the contrast between bare lava and the damp, green forest; it is the best reminder that this trail crosses more than one kind of landscape.

In the 1800s, workers processed pulu, the soft fiber from hāpuʻu tree ferns, for stuffing mattresses. The first known commercial sale was in 1847, and Hawaiʻi exported 788,000 pounds by 1862. Judge George Anson Byron Kaina established stations at Nāpau and north of Kīlauea’s summit. The Nāpau station was likely abandoned around 1867 after overharvesting; low stone walls are still visible beside the route.

The exposed lava gets strong sun, while rain and wet clothing can turn a long hike cold. Stone ahu can be hard to distinguish from black lava at first, so keep your eyes on the next marker. There is no drinking water at the trailheads or along the route; bring the full day’s supply (the park recommends four quarts per person per day), plus sun protection and rain gear. Overnight camping needs a backcountry permit. The 2024 flow buried most Nāpau campsites and the pit toilet; the remaining site near the overlook is limited to two tents and has no pit toilet.