Take Hwy 37 as described in the "Getting There" section but continue on south past the junction to the summit to where the road becomes Hwy 31. Follow this increasingly narrow, winding road toward Kaupo. The trail starts 1.45 miles up the roughly paved road .11 mile to the right (east) of the store on the left (landward or Mauka) side of the highway. (The store may or may not be open at any given time, so be sure to have acquired what you need for this hike before you get to here)
In order to gain the full 10,000 vertical on this trek you will have to make your way down the road and start at the beach about .8 mile and 320 vertical feet below the store. The most efficient way to do this is to go east .5 mile on the hwy, turning south on a side road and following it down to the beach another .3 mile. This is posted "no Trespassing" but appears to be state land so it should be ok to hike down the road to the ocean. Here is a detailed map with mileages for the start of this route:
Detail of the start of this route
Once at the right hand side of the Kaupo store, facing the mountain, go to the east .11 miles and turn uphill on the roughly paved single lane road. The trail starts out as a jeep road quickly turning into a regular trail. It goes on and off old grades, currenty used ranch roads and old overgrown roads but is easy to follow and has a pretty good supply of shade for much of the distance. This is private land until you cross the park boundary at 3.1 miles from the TH, but the owners have given hikers permission to pass. After about 3.8 miles more, pass the junction leading to the Paliku shelter taking the left fork. The most direct route to the summit is to always take the left forks for the rest of the trail. The last few hundred yards of trail are on the summit road, finally arriving at the 10,023 ' summit. Congratulations! You've just done over 10,000 vertical in one continuous hike! Now all you have to do is fill your water bottles at the visitor center and return on the same trail - (yeah, sure!)
The trail is rough in sections and there is no shade once in the upper valley so good footwear, a hat and sunscreen are neccesary. There is no water (unless you count the stock watering holes and tanks on the lower kaupo section of trail)for the entire 17.8 miles so bring plenty. (17.8 miles one way if you start at the shoreline; 15.6 miles one-way if you start at the regular trailhead.)You start out firmly in the tropics but end up in the subarctic so light gloves and a windbreaker may be useful as well, especially in winter months.
You are unlikely to see anyone on the Kaupo section of this trail and very few people, if any, until you are within about 4 miles of the summit on the Sliding Sands Trail so know what you are getting into and plan accordingly.
If you have information about this route that doesn't pertain to any of the other sections, please add it here.