Mauna Kea-Humu'ula Trail is a 14 mile lightly trafficked out and back trail located near Kamuela, HI that features a lake and is only recommended for very experienced adventurers. The trail is primarily used for hiking and is accessible from March until December.
Hike the highest mountain in Hawaii (in the world, measured from the sea floor), and enjoy views to Moana Loa and to the ocean as well as other islands. This is not a casual hike - come prepared with all the water, calories, and essential items a high-altitude experience demands. Park at the visitor center, self-register anytime, then join the trail a few hundred feet up the road on the left. Six miles of uphill trail with few switchbacks, consisting of loose cinder and rough lava, lay ahead. You will likely be alone - plan for self-reliance. Just below 13,000 feet the trail joins a paved portion of the service road, which, mostly unlaced below, provides a longer but suitable route back.
This is by far the hardest climb I have ever done! Definitely noticed the altitude, but still very worthwhile.
Hiked in April as part of preparing for Peru in May. Temps were in the upper 40s so we just wore long sleeve shirts which was just right. The initial trail has a lot of loose cinder that feels like hiking uphill in sand. Had some minor altitude symptoms the first time so we used Advil prior to the second time which helped. Wogging down in cinder leads to stops to empty shoes. Looking forward to Peru.
Make this a priority for your big island visit. Fantastic, rugged, remote. Acclimate first - going from hotel to 9.2K parking, then up over 13K before lunch impacted us. Come prepared - there's nothing out there but up, up, up. Worth every step, and the view to the ocean and other volcano are remarkable. My son and I did the roundtrip from the visitor center, 6:30 AM to 4 PM. As is typical, a clear morning turned to rain below us, and we stayed just ahead of the clouds which topped out at about 11K feet. We went to the observatories at about 13.5K or so, but didn't hike around to the summit access trail. This trail takes longer up than the six miles indicate - steep, unrelenting, and very loose in some areas - just hard, but not technical or risky. We took the access road back, which added a couple of miles, but we were gassed and felt this was a safer option as we hiked back down into a storm.
Having done an high altitude hike before, I thought I wouldn't have any problem doing this one. Error! Take time to acclimate to the altitude at the visitor center, it is worth it! So I made this 5-hours awesome hike while I had altitude sickness. But at least I could still take time to appreciate that desert view where you seem at the top of the world! Make sure to bring lots of water, and good warm clothes for when you get near the top.
We started at 12:15 PM, but I do not recomment it. For us it took 5 hours, but I know for many people it can take more, and you don't want to be caught by darkness. We saw the nice sunset at the top, and then proceeded to ask another tourist if he could take us down in his 4x4.
The hardest part is the first 3 hours. Then it's less steep. But keep in mind that as you go up, there's always less oxygen, so your heart has to work harder!
There seems to be almost nobody who climbs this mountain, which gives also, at some times, the sensation to be alone in the world. I greatly recommand it!
Five stars for the amazing scenery and the sense of accomplishment. Something less than that for the trail itself, which while impeccably maintained, is an absolute a$$-kicker. The first couple miles is on a 40 percent grade of loose cinder (almost like walking up a hill made of sand). For every 3 steps you walk up, you probably lose one of those from slippage. There are no switchbacks on this hike - just straight up. With a heavy pack, we usually average 2-3 miles an hour, here we were at just a shade under 1.5 an hour. You'll need a lot of water, because there isn't any cover, and you'll be sucking wind the whole time, but you won't mind because of the amazing views. We came from the Hilo side, and were in the clouds all the way until we turned off onto the Mauna Kea access road. While we couldn't see anything to the east because of the clouds, all of Mauna Loa and Hualalai were clear as day, and the panorama was spectacular. We started at 6:40 in the morning, and since we hand to be in Waimea by noon, we turned around at 9:10 after about 3.5 miles, so only halfway to the top. We could tell on our way down that a lot of people started around 7:00 (or perhaps they were just walking much faster than us). The walk down is MUCH faster, although you're likely to get cinder in your shoes, so consider bringing gaiters.