ABOVE: Miles of trails beckon hikers in the less frequented Kahuku Unit of Hawaii Volcanoes National Park.
Hawaii Volcanoes National Park, with its two active volcanoes where lava often flows, happy-face spiders grinning from the rainforest and sulfuric vents lending a surreal, post apocalyptic feel, is a bucket-list destination drawing 1.6 million visitors a year. Most come to explore the lava tubes and take in the glow at Halemaumau. Little do most of these visitors know that just an hour down the road lies the park’s Kahuku Unit, a secret held in plain sight. Over decades and in collaboration with many partners, HVNP has worked doggedly to acquire this parcel and preserve its natural and cultural resources. Visitors are going to need a bigger bucket.
The acquisition of three parcels over the past twenty-one years—the Kahuku Unit (2003), the Great Crack (2018) and recently Ala Waii (2022)—has added more than 120,000 acres to Hawaii Volcanoes National Park. These acquisitions lie entirely within the ahupuaa (traditional land division) of Kahuku, the biggest ahupuaa in the state, located in the jealously guarded Kau district. The people’s connection to the land runs deep on Hawaii Island’s remote southern wedge: Bumper stickers and T-shirts sold here read, “If you’re not from Kau, sucks to be you” and “Keep Kau Country.” The slogans lay bare residents’ pride in their aina (land) but also their fears for its future.
Those fears are not misplaced. Developers tried for decades to capitalize on Kau’s eighty miles of mostly untouched coastline. Indeed, each Kau acre added to the park was once privately held, making these acquisitions costly and slow. The 1,951 acres within the Great Crack parcel, first identified in 1975, took nearly half a century for the park to acquire. The Kahuku Unit, meanwhile, cost a whopping $22 million, purchased with the help of The Nature Conservancy. It took multi agency action by HVNP, the Three Mountain Alliance watershed partnership, the Trust for Public Land and others to secure these three parcels.
How to manage them was another matter. Park administrators knew they had to tap into Kau’s generational knowledge to design a sustainable plan, one that honors the park’s purpose to “perpetuate endemic Hawaiian ecosystems and the traditional Hawaiian culture connected to these landscapes.” From ancient petroglyphs and endangered endemic plants to sacred shrines and Pahu Manamana o Umi—a stone structure believed to have served as a compass for ancient navigators—these parcels tick all requisite boxes.
“These acquisitions required a lengthy planning process, including many thoughtful conversations with the Kau community,” says HVNP superintendent Rhonda Loh. “What came through loud and clear is that people love these areas, want to be actively involved in stewardship and worry about overcrowding. Their priority is to maintain a rural environment that provides intimate, immersive experiences.”
Judging from a recent Saturday at the Kahuku Unit, the furthest along of the three parcels in its development process, the plan is working. The collaboration between the community and the park is palpable here, where monthly coffee talks are often standing-room-only. At one recent event, park volunteers poured coffee and scrambled for additional chairs while locals like Clyde Boysen shared personal stories and photos of the day’s topic, io, the endangered Hawaiian hawk. “Io forage near our home, so we came specifically for this talk, but we love this part of the park,” Boysen says. “There’s a serenity and beauty to nature on the edge, in recovery, like you see here at Kahuku.”
An endemic io (Hawaiian hawk) perches in an ohia tree in the Kahuku Unit.
It’s no easy task restoring this land after 150 years of cattle ranching decimated critical habitat for endangered birds like io and uau (Hawaiian petrel), and plants including ahinahina (Kau silversword) and hoawa (royal cheesewood). Some species, like io, are found only on Hawaii Island, while others, like the Kau silversword, are even more specific; it’s found only in Kahuku. It’s already too late for alala, the Hawaiian crow, officially extinct in the wild after the last populations disappeared from Kahuku in the 1970s as more pasture land was created. (Several attempts to reintroduce captive-bred alala on Hawaii Island failed—io preyed on the crows.) Once the law of diminishing returns beset ranching, desperate ranchers introduced mouflon sheep and bison for private hunting safaris. Shrinking habitat, vanishing species and ungulates: The Kahuku Unit was a pending ecological disaster when the park assumed stewardship in 2003.
“Our kupuna tell us it’s part of a cycle. It’s not a disaster, it’s a hulihia event,” says Sierra McDaniel, natural resources program manager at HVNP. “In that cycle, hulihia is always followed by kulia—the recovery and restoration stage.” Implicit in this model of upheaval followed by rejuvenation is the impossibility to restore landscapes—natural and ethnographic—to precisely as they were before. “Given that we have all these invasive species, that we’ve had extinctions over the past two hundred years, the challenge is understanding the potential for this landscape now. Our strategy is to facilitate restoration of the forest, provide habitat and support high biodiversity.”
The first step in the strategy: Get rid of the cows. It took seven years to relocate the cattle to Kahua Ranch in Kohala. The second step was fencing out ungulates (and the occasional human), which damage the fragile ecosystem. By the time the park acquired the Kahuku Unit, the original eleven mouflon sheep brought in for trophy hunting had multiplied to three thousand. To give native species their best shot for survival, the entire unit was fenced in, and the remaining ungulates were culled by park staff and volunteer hunters from the community.
After the Kahuku Unit closes at 4 p.m., visitors often head to the Great Crack for a sunset hike.
The flower of the endemic ohia lehua.
In 2014, fence maintenance became an urgent priority when a fungal disease infected trees in the Kahuku Unit and elsewhere, causing rapid ohia death (ROD). Known as a “keystone species” in Hawaiian culture and ecology, the endemic ohia tree is essential for maintaining a balanced ecosystem and a healthy watershed. The nectar from its flowers are an important food source for endangered native birds, honeycreepers like iiwi and amakihi. Research from 2021 found that fenced areas were two to sixty-nine times less likely to have suspected ROD than unfenced. “Habitat prediction models for the end of the century indicate that Kahuku will be among the last, best spots for forest bird survival on the planet, so it’s important to protect this area from ROD. This needs to remain a viable place for those species when the time comes,” says McDaniel. She confirms that fencing is the park’s biggest, most expensive challenge.
The final piece of the forest restoration strategy entails beating back the aggressively invasive kikuyu grass on which the cows grazed to study how this land was used traditionally and what species thrived here. Scientists, like developers before them, were anxious to dig into the Kahuku ahupuaa, suspecting major discoveries lie beneath all that grass. “For decades, researchers knew there was an agricultural field system in Kau similar to the ones in Kohala and Kona but didn’t know where until the park acquired this parcel,” says Summer Roper Todd, HVNP cultural resources manager.
Bringing modern technology, paleobotany and geographic information system prediction models to bear, researchers from the University of Hawaii at Manoa, in partnership with the park, hit the archaeological jackpot. They discovered a thirty-seven-thousand-acre agricultural field system, believed to be the largest in the Pacific. “This system is huge,” says Roper Todd, “with several structures and miles of rock walls mauka to makai [mountain to sea] dating from the 1400s, indicating systematized farming of sweet potato that supported an expanding population in this area.”
"I took photos of the Puu o Lokuana Cinder Cone, inviting passing hikers to vote on which one I should paint," says HVNP artist in residence Dianna Miller, seen above left showing one of her works in progress at the Kahuku Unit's monthly Coffee Talk event.
Valuable pre-contact botanical and cultural information gathered through soil and fossil plant analysis is being applied to the park’s restoration plan. Atop the kuaiwi (rock walls) below which the uala (sweet potato) grew, ancient Hawaiians planted ko (sugarcane)—when rain combined with Kau’s notorious winds, it shimmied through the cane to create a natural sprinkler system. The ohia forests complemented this human-engineered microclimate by gathering scarce moisture, making it available for agriculture. “The evidence is right here for a forest restoration roadmap,” says McDaniel. “Ohia and koa grew here as well as other native trees, including lama [ebony], halapepe, alahea and iliahi [Hawaiian sandalwood].”
Other efforts are focused on preserving critically endangered species. By the late 1990s, habitat damage had pushed the Kau silversword to the brink of extinction. Not the average plant, this species grows only on the slopes of Mauna Loa and takes between ten and thirty years to flower, after which it dies. Knowing this, Junior Molcilio, a paniolo (cowboy) at Kahuku in its ranching heyday, lugged fencing up to five thousand feet, where silversword thrives, and erected a three-acre enclosure to protect the world’s last five hundred specimens.
“We have Molcilio to thank for the survival of the species at Kahuku,” says McDaniel. “When the park began stewarding Kahuku, we rebuilt his fence and collected wild ahinahina to save the remnant populations.” These specimens were moved to the Volcano Rare Plant Facility and cross-pollinated to maximize genetic diversity; the seeds were planted at Kahuku. Recently, a helicopter carried two hundred silverswords to establish a new population site at seven thousand feet. “Our goal is to restore Kau silversword to this entire area,” says McDaniel. “Spreading them out among several sites is key for protecting them from future lava flows.”
Miller heads out for a morning hike on the Puu o Lokuana Trail.
Stone ahu (cairns) built by the National Park Service guide the way across the 1868 lava flow on the Kahuku Unit's Puu o Lokuana Trail. (Visitors are strongly discouraged from building ahu of their own, in part because they could lead hikers astray on otherwise unmarked trails.)
Protecting sensitive species and restoring habitat are only part of a national park’s mission. There’s also the need for responsible public access. A well-maintained trail system of varying difficulty and terrain is part of the Kahuku Unit’s charm: Some trails allow cyclists and dogs, and several routes can be combined to provide a robust day hike. Not a hiker? Not a problem. A good portion of the Kahuku Unit is four-wheel-drive accessible, giving visitors of all ages and abilities the chance to behold kulia in action among some of the planet’s rarest life forms. While bucket-list traffic clogs the Kilauea summit, at Kahuku it’s rare to see another soul. Even on busy days this area is peaceful, with io soaring overhead, endangered birdsong bouncing from the walls of a forested pit crater and uninterrupted views of the Kau coast. Visitors are urged to kokua (help) prevent ROD by brushing off and spraying boots at trailhead quarantine stations.
An interim access plan is unfolding for the sixteen-thousand-acre makai side of the Kahuku ahupuaa, purchased by the Trust for Public Lands and transferred to the park in 2022. Known as the Kahuku-Pohue parcel, it is a natural and cultural lodestone, peppered with petroglyphs, fishing shrines, burial sites and anchialine ponds—vital habitat for opae ula, Hawaiian red shrimp. A section of the Ala Kahakai National Historic Trail shares the coastline here with the largest recorded ancient abrader stone quarry in the state, and endangered monk seals and hawksbill turtles haul out on Kahuku Beach to rest and nest.
A well-kept secret for generations of Kau families and cultural practitioners— particularly the pristine beach and coastal fishing grounds—access to this parcel is currently restricted, as it requires crossing private property among sensitive sacred sites. To help guide stewardship and access decisions, the park, together with the Hawaii Alliance for Community Based Economic Development, sought local input. “We heard many concerns about overuse at these heavily attended meetings. We want to proceed cautiously while at the same time protecting the area’s resources,” says Loh.
At the end of the steep trail to the Kahuku Unit’s pit crater, native habitat thrives on sheer, 250-foot walls and a forest rises from the inaccessible depths. Protected from hoofed ungulates and humans, endangered and rare species offer a glimpse into an ancient Hawaiian landscape.
Community input led to actions now underway to provide managed access to the Kahuku-Pohue parcel. First, pedestrian-only, day access will be permitted via a short connector trail being built by experts in traditional Hawaiian trail building and masonry from Puukohola Heiau National Historic Site; this trail will be entirely within park boundaries. Also necessary for public access is the installation of composting toilets, made possible by a donation from the Friends of Hawaii Volcanoes National Park. “For years there was talk about public access to Kahuku Beach. It’s exciting that the park is finally making it happen,” says resident Marri Werly.
Other well-kept Kau secrets acquired by HVNP are the Great Crack and Ala Waii, two contiguous parcels totaling 4,700 acres. These areas are cherished by residents for their rugged hiking opportunities through the Kau Desert Wilderness to the coastline. As hard to fathom as it is to photograph, the Great Crack is an eight-mile-long fissure measuring fifty feet wide and sixty-six feet deep in places. Odd formations including lava tubes and cinder cones dot the surreal landscape. “The geology and nature out here are awesome—they speak to you,” says Ocean View resident and avid hiker Simone van Harten.
Site planning for these two parcels is in its infancy—little is known about their cultural and natural heritage—and will be guided by future community input. “We’re working to control invasive fountain grass at the Great Crack, and preliminary archaeological surveys show there were seasonal villages and sacred sites throughout the area,” says McDaniel. One big question is how ancient Hawaiians used these parcels; another is what they were called. Ala Waii, for instance, is the name of the last developer and is being used simply as a placeholder. To better understand this slice of the Kahuku ahupuaa and reconnect people to the land, park managers are proposing a multidisciplinary archaeological-anthropological study, hoping lineal descendants can fill in the blanks. “There’s not a lot to do in Kau,” says park ranger Wendy Scott-Vance. “It makes me happy to see so many people enjoying this extraordinary area.”
