Visitors to Maui come to the island expecting a certain kind of natural experience: sparklingly clear ocean waters, palm trees swaying in the breeze, waterfalls tumbling into secluded pools amidst tropical jungles, and jagged fields of lava rock. Visitors would be excused if they didn’t expect to encounter a slice of the Pacific Northwest inexplicably plopped down on the slopes of Haleakala. That’s just what adventurous hikers can expect to find when they visit the magnificent forests of pines, cedars, cypresses, and, surprisingly, coast redwoods protected within the Kula Forest Reserve and Poli Poli State Recreation Reserve.
These forests came to be through reforestation efforts conducted in the 1920’s and 1930’s. The original slopes of Haleakala at the 5500’ to 7000’ level had been home to groves of native koa, mamane, and o’hia trees. After the introduction of cattle ranching and other domesticated animals ravaged these forests, the fertile earth within the island’s fog belt received thousands of saplings of imported trees, including coast redwood, Monterey cypress, Japanese sugi pines, Chinese cedars, mahogany, and pines.
Prodigious rainfall, permanently cool temperatures, and consistent fog banks create ideal climatic conditions for these trees. As a result, many of the trees – especially the redwoods – have reached impressive heights in a relatively short time. It’s entirely conceivable that the redwoods here could begin rivaling some of the mammoths on the northern California coast given a few more centuries in Maui’s famously benign climate.
The route presented here is not a complete record of the trail network at Poli Poli, nor is it the easiest route for visitors. I did not have the time when I hiked this route to cover the various smaller routes that would likely be more digestible for hikers looking to devote a chunk of their precious vacation to the trails. In order to compensate, I’ve approached this write-up from the perspective of describing multiple variations that you can use to break the route up into smaller chunks if you don’t want a 10+ mile route. Of course, the full route is a fantastic experience if you have the appetite for it. I present the route as the main part of the write-up while including all variations as they come up.
The first variation includes a moderate loop comprised of the Boundary Trail, Waiohouli Trail, and Waipoli Road. From the gate and cattle guard indicated in the directions, proceed southwest on Waipoli Road for 70 yards to the signed Boundary Trail trailhead, turning right. The Boundary Trail begins a lazy switchbacking descent through dense groves of pines. The initial mile contains many slippery sections that require careful attention lest you findeth thyself upon thy very buttocks (verily and forsooth!). Sporadic views open up downslope toward Kihei and Wailea, but the trail mostly sticks to the dense forest cover.
The slipperiness of the trail eases somewhat when the path reaches the boundary fence. At the boundary fence, the trail enters a dense grove of eucalyptus trees, whose shed leaves stabilize the footing somewhat. After dropping into and then out of a gulch, the trail climbs up onto a treeless hillside. Directly ahead, the stark contrast of eucalyptus on the right of the reserve’s boundary and massive coast redwoods to the left hints at the man-made nature of the forest. At 2.2 miles, the trail enters the coast redwood grove, which is tantamount to instant transportation to another world.
The dense redwood canopy effectively blots out the sunshine, creating the classic “cathedral effect” famous to coast redwood groves. Ferns grow here and there in the understory, but the shade is so complete that little grows below aside from the ferns. This is the primary difference between the northwest and Maui; Mauian plants are all sun worshippers, while northwest plants are used to being in the shade.
VARIATION: At 2.6 miles, you’ll reach the junction with the lower Waihouli Trail. If you wish to complete a shorter loop, turn left onto Waihouli and travel uphill through the redwoods, groves of pines, and then forest recovering from a 2007 fire to return to Waipoli Road. Turn left onto Waipoli Road to continue to the trailhead for a 5.5 mile loop (approximately).
Beyond the Waihouli Trail, the Boundary Trail hugs the boundary fence, which keeps feral goats, hogs, and cows out of the reserve. You’ll likely hear the bleatings of goats as they travel their own paths on the other side of the fence. The forest cover on the other side of the fence is comprised mainly of widely-spaced eucalyptus trees, which afford frequent views downslope when clouds bully the scenery into misty obscurity. On your side of the boundary, you’ll pass next through a grove of Monterey cypresses, sugi pines, and mahogany trees as you continue toward the old Poli Poli ranger structure 1.4 miles away.
At the ranger structure, you’ll encounter a junction with the Plum Trail and the Redwood Trail (Mark this junction, as it’s part of a shorter looping route from the Poli Poli Campground area). Continue straight on the Plum Trail to begin a climb through a varied forest including more sugi pines, redwoods, Monterey cypresses, and Chinese cypresses. The understory is often thick with tropical vegetation, with ferns figuring prominently.
At 4.5 miles, you’ll encounter a sign warning of falling trees. You’re entering the burn zone from a 2007 fire that wiped out considerable acreage of planted Monterey Cypresses. Many skeletal hulks of trees tower over the trail, and these trees are known to topple. This is not a good place for an extended break, especially if the winds are high. Continue progressing south as you approach the junction with the Haleakala Ridge Trail.
The trail merges with the Haleakala Ridge Trail and continues its uphill progression through a much sparser forest of eucalyptus and pine. Occasional views back down Haleakala Ridge reach the ocean and La Perouse Bay at the coast, again when not occluded by cloud cover.
At 6.2 miles, the trail comes to another junction with the Poli Poli Trail, which will allow you to circumvent an unnecessary uphill detour leading toward the Skyline Trail descending from Haleakala’s summit. The Poli Poli Trail will take you through more recovering forest to a large opening dubbed “the Ballpark” for its spacious circular confines. Shaded picnic benches present an opportune spot for a rest break.
The Poli Poli Trail ends where Waipoli Road begins, and most hikers will elect to take Waipoli Road back to the trailhead. About one hundred yards from the Ballpark, you’ll pass a gated road leading down to the closed campground on the left. This also serves as the junction for the Redwood Trail. If you want to skip the Boundary Trail/Waiohouli Route, and you have a 4WD vehicle that the state requires you use on Waipoli Road, you can follow the following variation from the closed campground for a satisfying 5-6 mile loop:
Otherwise, you’ll have an easy but somewhat monotonous 3.4 mile walk back to the trailhead via Waipoli Road. The road passes through the burn zone, which is often lined by pioneering pines. At 10.2 miles if you’re following the full loop, you’ll reach the conclusion of your hike.
The trail on all sections is well-marked and reasonably easy to follow. The first few miles of the boundary trail can get pretty slippery after rainfall, which is more common during winter, spring, and fall. Some parts of the trail are eroded and a bit difficult for footing. In some places, it looks like wild hogs have rooted into the soil for food, thus creating a lot of disturbed soil.
Poli Poli's campground would be the best option, but it's not currently open. The nearest adjacent campground is Hosmer Grove in Haleakala National Park.
From Kahalui, follow the Hana Highway (HI-36) east to a junction with the Haleakala Highway (HI-37). Follow the Haleakala Highway southeast for 14.3 miles to HI-377. Turn left onto HI-377. After only .4 miles, turn right onto Waipoli Road. Waipoli Road squiggles and wiggles its way up the slopes of Haleakala. After 5.9 miles on Waipoli Road, you'll come to a gate indicating 4WD vehicles beyond this point. Boundary Trail is 70 yards southwest from this gate.