Mauna Kea Observatories

Mauna Kea Observatories

Mauna Kea is the tallest of all the world’s sea mountains and also stands above the rest of the US State of Hawaii, an archipelago entirely made up of volcanic islands.

Name: Mauna Kea
Height: 4,205 m (13,796 ft)
Location: Hawaii, USA
First Climbed: 26 August 1823 by Joseph F Goodrich
Climb Time: 8-10 hours
Best Time to Climb: April-October, though open year-round.


The tallest mountain in the world (when measured from its submerged base), Mauna Kea (4,205 m/ 13,796 ft) is a hidden giant of the mountain world. Like many submerged but under appreciated volcanoes, which can cover huge areas (Tamu Massif), the full extent of Mauna Kea is hard to comprehend from the massif we witness above the waves.

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It’s snow-capped peak is also visible on a clear day from sea-level, rising sharply to the summit cone unlike its gently graduated neighbour Mauna Loa (4,170 m/ 13,681 ft). And, with the right off-road vehicle, you can also drive from sea to summit within two hours!

With winter skiiing, year-round hiking and four other volcanoes making up the Big Island of Hawaii, Mauna Kea can give you a number of thrills and challenges. And at the end, you can gaze skyward from the summit and see the whole universe stretch out before you.

By some measures, Mauna Kea is the top of our world. And you can simply walk up there and (almost) touch the stars. 

Photo by  USGS

Photo by USGS


The legends that surround Mauna Kea, or Maunakea, and its volcanic neighbours give context to their violent pasts and celebrate their uniqueness in this tropical environment.

Mauna Kea means ‘White Mountain’ in Hawaiian, though a traditional name for the peak is Mauna a Wākea, ‘the mountain of Wākea’. This name links it to the indigenous legends, which suppose this mountain was the first born son of Wākea and Papa, the great ancestors of the entire Hawaiian race.

Another legend links Mauna Kea and Mauna Loa. It says they are the domains of two goddesses, Poliahu and Pele

Combative and disagreeable, these goddesses’s rivalry creates the violent earthquakes and eruptions that have been the uncertain landscape on which Hawaiians must have lived since they first arrived in the archipelago.

In the modern world, Mauna Kea’s importance is probably most valued by astronomers. Gazing upward from above the clouds, the Mauna Kea Observatories (MKO) are arranged within the large Astronomy Precinct, which stretches (and continues to expand) beyond the summit and down the upper slopes. 

An arid site above the cloud line, Mauna Kea proved the optimum location to garner the clearest images from a ground-based location (as opposed to from a satellite. The first images were seen in 1970, three years after building work began.

Today, 13 telescopes in 12 facilities, funded by organisations and education institutes from around the world, investigate our starry skies. 

But this project is not without controversy. Conservationists have argued for the protection of bird and animal habitats including the endangered Palila. Locals have also argued against the unsightliness of the white domes and the indigenous kānaka ‘ōiwi claim this use of the mountain is a desecration of sacred Hawaiian land. 

At the moment it appears modern science is winning the argument.

This sacred land also stretches to Lake Waiau, around 2.5 km (1.5 miles) from the summit. It is the highest alpine lake in the State and one of the highest in the USA. However, it is quite small and only about 3 m (10 feet) deep. 

Tradition states that Hawaiians would place their newborn baby’s placenta into this lake to give them the strength of the mountain and otherwise leave the lake undisturbed. Probably best to follow that tradition, for your own sake too!



Mauna Kea is not a single peak, but rather a series of volcanic cones lining a huge massif. Coloured red or black, these cones reflect the history of eruptions from numerous vents, with the true summit being found on the largest of these cones (Puu Wekiu).

Hawaiian geography.

There are eight principal islands that make up the US State of Hawaii, though only six have a significant human population. Each of these islands are the visible tops of a chain of volcanoes that stretches for around 5,000 km (3,106 miles) out into the North Pacific Ocean. Hawaii’s islands are the youngest part of the chain at 1 to 5 million years old, compared to the 83 million year old formations found in the far north-west of the chain.

Mauna Kea sits in the northern reaches of the Big Island of Hawaii at the most south-easterly point of Hawaii. It is considered a dormant volcano, with its last significant eruption some 4,500 years ago and last identifiable activity dating back to around 1650. This does not mean it is extinct though, and further eruptions are expected in the future, though perhaps not in our lifetimes.

Taking up the majority of the island is the younger and larger volcano, Mauna Loa. It has shallower sloping sides (reflecting its younger growth phase, see below) and erupts every few decades. 

The three other volcanoes that makes up the island are Kohala (1,670 m/ 5,479 ft, north-west), Hualālai (2,521 m/ 8,271 ft, west) and Kīlauea (1,247 m/ 4,091 ft, south). Kīlauea is the most active and youngest, and has the local nickname ‘the Mountain of Fire’. 

In total, Hawaii’s islands are created from 15 individual volcanoes, creating impressive, dramatic lands across the chain.

Mountain Building.

The process by which these volcanoes are built is called ‘shield building’ and covers a great number of different phases. The name refers to the wide, flat appearance of these volcanoes once they have risen, a shape reminiscent of a warrior’s shield. 

To simplify the process, they are built by accumulating layers of lava lying on top of one another. This occurs first underwater then above sea level, creating the islands we see today. 

Mauna Kea, along with Hualālai and Kohala are older volcanoes and have passed this ‘shield-building stage’ and are ‘post-shield’. This means they are erupting less often, the lava they eject is thicker so settles higher on the slopes, and the processes of erosion are catching up, and sometimes overtaking, the processes of growth.

This leads these older volcanoes to be steeper, more jagged and to have the potential for steep valleys and coral reefs below the shoreline. Mauna Kea reflects many of the qualities of this stage, with upper slopes twice the steepness of the younger Mauna Loa.


While they no longer stretch down the shallow slopes, geologists have found that Hawaii’s barmy climate was once chilled enough to house large glaciers on Mauna Kea’s slopes. Glacial moraines and other evidence reflect several ice age formations, the last ending around 13,000 years ago. 

Today, both Mauna Kea and Mauna Loa are high enough to receive a winter snow fall to a depth of several metres. So while there are no glaciers, Mauna Kea can still offer enough snowpack to attract skiers and snowboarders from the world over, even if only for a short time each year.



With a landscape regularly described as desolate, the red and black earth summit area of Mauna Kea looks more like the moon than the lush greens found across most of lowland Hawaii. 

Yet this place is far from devoid of vegetation. The flora was, in fact, the cause of one of the earliest ascents of Mauna Kea, with James Macrae recording many species on a summit adventure in 1825.

At lower elevations, native trees such as the māmane tree are found in increasingly rare clumps between areas of grassland or bare earth. These trees create an environment for understory plants who receive drips of water from fog that gathers on the tree’s leaves. They also have two species of mint vines that climb their trunks and branches. 

Given its central role in the lowland ecosystem, the loss of this tree, which is a current concern, would also impact several otherplant species. 

Above 3,000 m (9,842 ft), the alpine vegetation becomes more sparse and less diverse. This area includes shrublands, grass desert and stone desert, with shrubs, grasses, ferns and lichens making up most of the inhabitants. 

The low-lying shrubs of Puūkiawe, ‘Ōhelo and Mauna Kea dubautia are all endemic to the mountain. Grasses such as Hawaiian bentgrass are found in these areas too. One of the first plants to be recorded, ‘Āhinahina, also known as Mauna Kea silversword, is a native fern first noted by Macrae but now is rarely observable with dwindling numbers. 

In the alpine stone desert, only lichens growing on the larger rocks survive the arid, high altitude conditions. 


The majority of animal life on Mauna Kea consists of birds and bugs. At the summit, there is a significant population of predatory and scavenging arthropods, with at least 21 resident species. Creatures like Wēkiu bugs can be found around the cinder cones, foraging for other bugs and unfortunate flying insects that are blown up from lower elevations, often dying en route. 

The bird life at subalpine and alpine levels is plentiful. Many rely on both the large population of bugs and the specific vegetation found lower on the mountain. These include the Palila, ‘Amakihi, ‘Apapane, ‘Elepaio, ‘Akiapola’au and ‘I’iwi. All these birds rely on the māmane tree as a primary food source, and its declining abundance is a worry for these species too.

Most species found on Mauna Kea are incredibly sensitive to habitat changes, most being native and developing as they have on such a small landscape. As such, several species are now endangered as humans encroach and alter their habitat. 

The Palilia, an endangered species of bird that finds itself part for the arguments against the MKO, is one such endemic creature, found only in specific sections of Mauna Kea. 

It represents the last finch-billed species of Hawaiian honeycreeper and has become threatened in recent years. Without the māmane tree (see above), this bird loses its principal food source, the tree’s immature seeds.

The mountain is home to a bat too: the native Hawaiian hoary bat. This tiny creature has recently been proven a distinct species from the common hoary bat, so may be in line for a name change! However, like many of the flying creatures on this mountain, this bat is listed as endangered.


Though various family shrines created by indigenous peoples existed near the summit, it is unlikely more than a few ever actually attempted to reach the summit. The summit area is sacred to traditional populations and is under a strict kapu, traditional laws forbidding access.

The first recorded ascent was on 26 August 1823 by Joseph F Goodrich. The American missionary achieved the feat in one day, though observing several stone arrangements en route, he is known to have suggested himself that he doubted whether he really was the first to have arrived at the summit. 

During the same ascent he visited Lake Waiau and recorded four ecosystems from the base to the summit, work that remains a good guide to today’s understanding of the habitat. 


Given the steady slopes on most of Mauna Kea, it’ll be no surprise that the routes to the summit are all non-technical walk ups.

The chief dangers posed on Mauna Kea are the altitude and misjudging the length of the hike and so descending after dusk. All hikers are requested to register at VIS before leaving and reporting your safe return when you get down.

The primary route, the Mauna Kea/Humuula Trail, begins near to the Visitor Information Station (VIS) (2,804 m/ 9,200 ft), accessible by the 9.5 km (6-mile) Summit road. 

Sections of the hike follow the road (at the beginning and end of the trail), with the rest of the walking over loose scree gravel and some larger volcanic rock. On average, the return trip takes 8-10 hours and stretches over 18.5 km (11.5 miles).

The trail climbs steadily uphill for most of the ascent, though it steepens at the summit cone. The trail skirts along the western edges of many of the minor vents lower down the slopes before heading for the gap between Puu Warau (3,969 m/ 13,020 ft) and Puu Hau Kea (4,099 m/ 13,447 ft) passing close by to Lake Waiau. 

Rounding the northern side of Puu Hau Kea, the route then traverses the south-western slopes of the summit cone beforecutting back on itself to gain the northern slopes via the western flank. This extreme switchback navigates the mountain’s steepest slopes that rise from 3,900 m (12,800 ft) until 3,993 m (13,100 ft). 

The route then gains the summit by joining the dirt road south, though the true summit is about 400 m (1,300 ft) away from the rest of the summit plateau (Puu Wekia being the larger plateau). 

The return follows the same route back down the mountain. 


The summit of Mauna Kea is reachable by 4x4 vehicles, with a paved road only up to the VIS (2,804 m/ 9,200 ft) followed by a steep gravel track. Many car hire companies also ban you from these roads for fear of damage. 

Given that you begin the journey at sea level, and can drive to the summit within two hours, the real issue with this route is altitude sickness that is more possible as you ascend so quickly. Scuba divers are not allowed to ascend the peak within 24 hours of a dive, otherwise they risk the bends.

A longer adventure is the week-long trek from sea-level to summit of Mauna Loa, beginning at Ainahou in the north-west. This trek climbs the full elevation of Mauna Loa, following a number of existing trails (Keauhou Trail, Crater Rim Trail, Mauna Loa Trail and Summit Trail). This account suggests spending the penultimate night in the Mauna Loa Summit Cabin.

Alternatively, take the shorter trek from Hilo Bay to the summit of Mauna Kea. This idea is taken to an extreme by ultra-runners, who run the 64.7 km (40.2 miles) one-way trip, leaving around 3 am to reach the summit the following afternoon. Slower moving hikers would be advised to plan one or two overnights en route. 

This route is also a renowned cycling challenge. It is considered the hardest ascent cycle in the world as it slowly ascends on a median incline of 6.5%.

Mauna Kea also is also popular among skiers and snowboarders. Although not an official ski resort, there are still well known routes winding between the minor summits and vents that line the southern slopes, accessed by the Summit road. Hawaii’s Ski Club offers more information on how to enjoy an unexpectedly polar adventure on this tropical archipelago.

Hawaii is typically reached by plane to the capital Honolulu. This is on the far north-westerly island of the chain, so connecting local flights or boat trips are required to arrive at the Big Island and Mauna Kea.