The maintained Mauna Kea Trail is 6 miles in length (one way) and climbs 4576 ft (1395 m), starting from the Onizuka Visitor Center, which is at 9200 ft (2804 m). The trail loosely parallels a partially paved summit road, and from the Mauna Kea Ice Age Reserve boundary at 13200 feet to the summit road's high point of 13700 feet, actually follows the road. Getting to the summit from road's end requires a mere 5-15 minute walk and 100 feet of elevation gan. The vast majority of "mountaineers" drive to road's end, which can be kind of discouraging for hikers, especially when the altitude starts kicking in. Aside from the moral superiority you can enjoy from hiking, you'll take in splendid and wild views along the way. (NB: Hitchhiking is not unheard of.)
An interesting side trip is the short jaunt to Lake Waiau, a very shallow lake (no more than 10 ft deep) about a mile and a half from the summit. You aren't supposed to disturb the lake, and you probably wouldn't want to since Hawaiians used to bring the umbilical cords of their babies here and place them in the lake to give them "the strength of the mountain". If you must drink from the lake, however, today's modern filtration systems should take care of any lingering placental matter.
Previously, most car rental contracts prohibited travel on Saddle Road, although in April, 2015, asaking11 noted: "Most rental companies now allow rental cars on Saddle Road. There are even a handful of them that will allow you to take them to the visitor center." A car is definitely the best way to get there. Not by car: The problem is the buses don't use Saddle Road. So, use a car by proxy. (Hitchhike). But seriously, don't worry about the car rental agencies? policy. They don?t dust the tires for Mauna Kea dust or anything.
The trailhead for the Mauna Kea Trail is a hundred yards northwest of Onizuka Visitor Center.
Note that Mauna Kea is not in the Hawaii Volcanoes National Park. You would be thinking of Mauna Loa, the second tallest peak in Hawaii. Mauna Kea is leased to the University of Hawaii from the 12,000-foot level and up. So they generally take a not-for-profit approach. Hallujah.
If you'd like to part with your money, you can use professional guides http://maunakea.com. This would also solve the "how to get there" problem, if you don't have a car, since these guides will pick you up from centrally located STARBUCKS (TM) in three different places on the Big Island, which can be reached by bus.
Wildlife conservation: Outside the Mauna Kea Ice Age Natural Reserve, hunting is allowed and common. Also, it is interesting to note that there was a very heartfelt and effective campaign to remove mouflon game sheep from Mauna Kea.
Current road conditions to the summit: call (808) 969-3218.
Visitor Center Hours: (808) 961-2180 website:http://www.ifa.hawaii.edu/info/vis/
Keep in mind there is no food or gas available on Mauna Kea.
Much of the "proof" of glaciers seems to center around the presence of native adze quarries. The natives set up summer residences in excavated caves and spent the months mining a rare, extremely hard volcanic rock that geologists believe could only have been formed by lava intruded under an existing snow or ice field. The rock was prized throughout the Hawaiian islands for use in a variety of stone implements. Beware of carrying off a souvenir, however. Aside from the fact that this is illegal, we can learn from Greg Brady and Scooby Doo, among others, that taking such souvenirs from Hawaii leads to bad luck and zany adventures.
Still, the line between semi-permanent snow field and true glacier is thin. It is possible, even probable, that Mauna Kea had glaciers on its slopes in the late Pliestocene or even in the more recent global cold spells (8000 years ago, for instance). However, given the high frequency of volcanic eruptive events, most, if not all surface expression of glaciers from 8000 years ago will be fully covered by lava today. In any event, the gullies on the mountain's south face are thought to have resulted from snowmelt from glaciers/semi-permanent snowfields.
Lake Waiau, at 13200 feet, was exploited as a source of drinking water by the native Hawaiians at the adze quarries. The shallow lake, which sits in a small crater on the Pu'u Waiau cinder cone, is curiously thought to be fed by melting permafrost. Still, one cannot ignore the possibility of some spring feeding, as the highly porous/permeable volcanic rock produces many other marked springs.
Lava Lovers: Mauna Kea is a dormant volcano. In technical terms, Mauna Kea is a classic shield volcano. They say that it could erupt in the foreseeable future (geologically speaking).
As most people know, Mauna Kea's summit region is home to a great many large telescopes and other space observation instruments. While there are higher mountains and mountains with dryer weather, the atmosphere above Mauna Kea is world-renowned for its lack of atmospheric "wind shear", which causes distortion in visible images.
Mauna Kea from Highway 190 near Waimea (Morgan Brown)
Mauna Loa from lower section of Mauna Kea Trail (Morgan Brown)
360° panorama from Mauna Kea's true summit (Morgan Brown)
Mauna Kea's telescopes from highpoint of Summit Road (Morgan Brown)