Getting to the Kaupo Trailhead
The Kaupo Trailhead is located at the end of a sideroad that leads uphill from the town of Kaupo. The sideroad starts approximately 200 yards east of the Kaupo Store, on the Piilani Highway, and leads upslope. The total distance from Piilani highway to the trailhead is somewhat over 2 km (about 1.4 miles). Many people choose to drive to the trailhead, but of course it is also possible to walk it. When we did the Kaupo Trail, we decided to do it on foot. We additionally decided to do a hike starting right from sea level, so in our case we made our way down to the shore near the Huialoha church, then walked up along the highway to Kaupo, then up the side road to the trailhead. Doing all of that adds a total of 4.3 km (2.6 miles) of distance.
Haleakala from Mokulau Beach
The drive (or walk) up the access road is quite nice. The ranch and farm land that the road passes through is quite pleasant, and the road itself is often a very nice twin track through green grass. The road passes a few tidy-looking homesteads.
After following the road about a mile mostly directly uphill, it turns left and proceeds on the level for a few hundred more yards through a shady, lava rock-wall lined area, before arriving at the Kaupo Trailhead, where there is a big National Park Service sign. There is a grassy section available for car parking. A closed car gate blocks the road here, but a small hiker gate is unlocked allows access to the start of the trail.
Now that we've gotten all of the preliminaries out of the way, it is time to start describing the Kaupo Trail itself.
The Kaupo Trail climbs the southern flanks of Haleakala, gaining access to the crater floor via a large wide opening called the Kaupo Gap. The lower initial part of the Kaupo Trail is not actually on park land; it crosses the private lands of the Kaupo Ranch. An agreed-upon access route has been established for the Kaupo Trail and the park service has placed numerous 'trail' posts to help hikers stay on the route. In a couple of places it is easy to get off track.
Crossing through the access gate at the trailhead, the trail follows a gravel driveway. The first few posts are prominent and easy to follow. In minutes, the gravel driveway bends to the right, leading towards a very nice ranch house. Do not go up towards the house. Instead, look left, and you will see a fainter side road that heads slightly downhill and through a fence. If you look closely, you'll also see a park service trail sign.
Once past the ranch-house section, a set of fairly obvious park sign posts lead northward through a grassy pasture. The tread through the grass is very faint here, so make sure you look for the next trail sign post before heading off in any direction.
The trail continues mostly in a northerly direction, climbing gradually as it passes through stretches of shady forest, small open fields, and along and across old grassy farm roads. Again, there are enough signposts to keep you on track, but a bit of alertness and intuitiveness for the right route are pluses.
Private Land notice, Kaupo Trail
At about the 2,000-foot level, after climbing over a gate that had been wired shut when we were there (but with a trail sign clearly showing it was the right way to go), you emerge into a substantially more open area of pastures, and the first bit of views back down towards the coast.
The next stretch of the Kaupo Trail ascends through mostly open pastures, following an old farm track. The grade is steeper here, and in places there are faint side-roads that you should not follow. Carefully look for NPS trail posts, and if you haven't seen one for a while, consider back-tracking to the last known one (either that or consult the GPS track I have of the trail).
The pastures open wider and wider as you climb higher. Occasionally there is a small tank or a big innertube filled with water, presumably for irrigation or for cattle. If you are short on water, these could be useful as emergency sources (with proper filtering, of course).
Along the Middle Kaupo Trail
Up until about 3,000 feet, the Kaupo Trail climbs through the wide open slopes that spread out below the Kaupo Gap. Above that, the trail starts to head to the right (north-east), angling towards the right-hand wall of the gap. The open pasture starts to become more closed-in with trees.
Arriving at Park Boundary