Mauna Loa Volcano

Mauna Loa Volcano Facts

Country:United States
Coordinates: 19°28'46"N 155°36'10" W
Elevation: 4,169 m / 13,677 ft
Volcano type: Shield volcano
Typical eruption type: Hawaiian
Recent eruptions:Mar-Apr 1984
Activity status:active

Mauna Loa Volcano is located on Hawaiian Big Island and it holds a couple of world records: it's the largest active volcano and also the largest mountain on Earth. If measured from its base at the ocean floor, it is over 9 km (30,000 ft) high, which is higher than Mt. Everest. This shield volcano has been formed slowly over hundreds of thousands of years by thousands of its eruptions resulting in large volumes of its lava flows. Because the lava from Mauna Loa, like from other Hawaiian volcanoes, has a low viscosity (is more fluid), it tends to create long, relatively thin flows, allowing, in time, for build up of many layers of it over a large area, creating a volcano mountain shaped like a shield.

Characteristic for Mauna Loa are non-violent eruptions, in form of lava flows and lava fountains (such type of eruptions is called 'Hawaiian style'). Despite the above Mauna Loa is considered the most dangerous volcano in Hawaii because it has a potential of eruptions much greater than Kilauea and it can generate lava flows long and voluminous enough to reach and seriously damage the nearby city of Hilo.

Most visitors to the Big Island just admire the view of this magnificent volcano, but a few decide to climb it. Although a hike to the summit of Mauna Loa is a quite long and strenuous walk, it's very rewarding and for those fit enough, worth considering. It's best to plan such journey for 2 to 4 days, but it's also possible to reach the summit and return in one day, but such itinerary doesn't give much time to really explore the volcano. The major difficulty in climbing Mauna Loa comes from the fact that most of the trails are at high elevations and over rocky terrain, making the walk slow and exhausting. Altitude sickness affects many Mauna Loa hikers, usually on altitudes above 3,000 m (10,000 ft). The climate is also a factor as it varies from tropical at the sea level to the sub-arctic at the summit. During the night temperatures drop below zero and during the day weather conditions can change very fast. Most often the weather is clear and sunny, but a driving rain and strong wind can occur any time of the year. Snowing is also not uncommon.

Mauna Loa Trails Map, Hawaii Volcanoes National Park Map
Mauna Loa Volcano Trails. Modified from map by National Park Service

There are two cabins on Mauna Loa for hikers: the Red Hill cabin and the Mauna Loa cabin. Because the space in them is limited, if you plan to spend a night in one of them, you must obtain a permit from the Hawaiian Volcanoes National Park at Kilauea Visitor Center. A note from the park website: "Permits are issued on a first-come basis no earlier than the day before your hike. Stays are limited to 3 nights per site; group size is limited to 8 people. A total of 8 people are allowed per night at the Pu'u 'Ula'ula (Red Hill) cabin, and 12 people at the Mauna Loa cabin."

There is limited water supply in the cabins and the water there needs to be purified. For the hike you will need warm clothing, enough food, a lot of water, sunscreen, sunglasses, good hiking shoes/boots, sleeping bag, rain pants and jacket, first aid kit and flashlight. Below are brief descriptions of trails that lead to the summit of Mauna Loa volcano. Another third option is to hire a helicopter to take you to there - much more expensive but possible and convenient... Or take an airplane tour and fly above the summit...

Observatory Trail

Mauna Loa Volcano summit crater
Mauna Loa Summit Crater. Photograph by Lauren Bacon

This is the shortest trail to Mauna Loa volcano summit. The trail begins at the Weather Observatory, at the altitude of 3,399 m (11,150 ft) where there is a public parking lot, but to get there you need a four-wheel-drive vehicle. It takes about two hours to drive to the Weather Observatory trailhead via Saddle Road from the the Kilauea Visitor Center. The trail is 20 km (12.4 mi) round trip and can be completed in one day but better option is to stay overnight at the Mauna Loa cabin.

Do not leave from the Observatory after 10:00 am. The first part of the trail, 6.1 km (3.8 mi) leads to a junction (North Pit) from where you can continue on the Summit Trail to the summit or on the Cabin Trail to the Mauna Loa Cabin. From the North Pit the trail to the summit has elevation gain 176 m (577 ft), length of 4.4 km (2.7 mi) and takes about 1.5 to 2 hours, with almost the entire part of the trail at altitude above 4,000 m (13,000 ft). The distance to the cabin (at 4,039 m / 13,250 ft altitude) is about 3 km (1.9 mi).

Mauna Loa Trail

This is the longest but less strenuous trail to reach the summit of Mauna Loa volcano. It takes from 20 to 22 hours to hike 77 km (48 mi) and most people plan it for 3 days to hike to the summit and 2 days for the walk back. This trail is also the most popular because, due to longer hiking time, it minimizes the possibility of altitude sickness. The first part of the trail starts from the Mauna Loa Lookout. You can get there by driving up Mauna Loa Road; leave the car at the parking lot at the end of the road. Note that there is no drinking water there. The first hike, 12 km (7.5 mi), is to the Red Hill cabin that lies on the west side of Pu'u 'Ula'ula spatter cone, at the altitude of 4,039 m (10,035 ft). There are spectacular views of Kilauea from this part of the trail. The Red Hill cabin is where you spend the night. The second part of the trail is from the Red Hill cabin to Mauna Loa Cabin - 18.7 km (11.5 mi). You will see several interesting sights on this part of the trail: the Pukauahi Cone, the Dewey Cone or the Steaming Cone. Stay in the Mauna Loa Cabin overnight. Next morning hike back from the cabin, following the Cabin Trail to the junction with the Observatory and Summit trails and follow the Summit Trail to reach the summit of Mauna Loa.

Ainapo Trail

This is the steepest and most difficult trail to the summit of Mauna Loa. Normally regular tourists don't even attempt to take it. We only mention it here because it's marked on official maps...

Other Hawaiian Volcanoes: Kilauea Volcano  •  Haleakala Volcano