Hawai'i Volcanoes National Park
Round Trip Mileage: 2.5 miles to the top of Pu'u Huluhulu, another mile if you add the short loop to the south of the trailhead.
Elevation Gain: 165 feet
Gear: Bring what you need for a short dayhike. This hike is higher in elevation, so expect chillier temperatures and prepare for rain.
Trail Guide: Download an interpretive guide from the National Park Service for this hike (pdf).
Map: Topographical Map of Pu'u Huluhulu
Overview: Literally meaning "hairy hill," this is a nice hike along an interpretive trail to the top of an old Pu'u that is now overgrown with rainforest. The top of the Pu'u can be a good vantage point on Pu'u ʻŌʻō, the current eruption site, especially at night or with binoculars or a telephoto lens. Don't confuse this Pu'u with another of the same name along the Saddle Road in the High Country.
Getting to the Trailhead: From the Park entrance, drive about 50 feet and turn south on Crater Rim Drive. Follow Crater Rim Drive to Chain of the Craters Road. On the Chain of the Craters road, find the Mauna Ulu parking area at the end of a short road that departs the main road between the 3 and 4 mile markers. The spur road dead-ends into a roundabout with a small parking area with a restroom. The trailhead has a register. There is sometimes a Ranger or Park volunteer stationed here.
The Hike: From the parking area, walk to the end of the paved road and find a trail register next to the beginning of the hike. The trail is well-marked with ahu (cairns) as you travel through lava flows from several time periods on the way to the Pu'u. At the base of the Pu'u, climb north for about a hundred feet to the top of the Pu'u to a concrete viewing area. Enjoy the view of Pu'u ʻŌʻō, the current eruption site, Mauna Ulu, and the surrounding area. Retrace your steps back to the trailhead. If you're interested in getting closer to Pu'u ʻŌʻō, find out more about the Napaū Trail, the closest you can currently get to it. When you return to the trailhead, consider hiking the quick spur loop to the south to check out some fascinating lava formations. This area requires no permit. The trailhead isn’t obvious. From the main trailhead with the register, walk the rest of the road until you see another trailhead on the south side of the road. You can do the quick loop in either direction. It will take you past many interesting lava features, including several lava trees. Be sure to check out the colorful lava within some of the vents along the hike. If you started the loop in the forested part, you’ll get dropped off near the road just east of where you started.
Mauna Ulu (literally growing mountain) is the large shield volcano to the south of Pu’u Huluhulu and is also accessible without a permit. You should check in with the Visitor’s Center to see if this hike is currently safe. There is no trail, but the best way to access the crater is to hike a shallow lava draw on the north side. Be especially careful near the edge – it can collapse at any time. The lava around your feet can also collapse at any time. Mauna Ulu erupted until 1974 and is the reason why there is a new Chain of the Craters road. It still spews lots of dangerous gas. Respect this dangerous place if you choose to attempt this short hike.