Mauna Loa Observatory

Mauna Loa Observatory in HI: a road built through lava

Mauna Loa Observatory is a premier atmospheric research facility at an elevation of 3.402m (11,161ft) above the sea level, located in the U.S. state of Hawai’i in the Pacific Ocean. Do not take this drive if you have respiratory problems or any type of heart condition. It's one of the highest paved roads of the country.

The road to the summit is called Mauna Loa Scenic Drive (or Mauna Loa Observatory Road). It’s a 17-mile (one way) roughly paved narrow road. The Hawaiian name "Mauna Loa" means "Long Mountain". Don’t stuff your belly too much. Eventually, you might feel vomiting temptations while climbing circuitous roads at higher altitudes. The road was built in 1950's in a lunar landscape. It’s a road built through lava.

Is Mauna Loa road steep?

The drive is pretty steep. Starting from Saddle Road, at 2.001m above the sea level, the ascent is 17,5 miles (28.1km long). Over this distance, the elevation gain is 1.401 meters. The average gradient is 4.98%.

Is Mauna Loa road dangerous?

This narrow but asphalted runway leads through solidified lava up to the observatory. Having a closer look at the road's rough, patchy pavement, the thin white line down the middle of the pavement is a "fog line" to guide drivers when visibility is poor. The beginning of the road has deteriorated a bit and contains potholes so be a bit careful. It's a one lane road with nothing but volcanic rock on both sides. The road is single lane and has many blind hills and turns. Pull off to the side and stop the car while on the phone, and fill your car with gas before leaving for the observatory. There is no gas available at the observatory. The road starts from the Saddle Road. Offering fantastic views, colorful lava and a number of interesting stops along the way, this drive can be done in any car. The best weather for this road is as clear a day as possible. Often there will be Hilo-side clouds but the middle of the saddle, should be clear. The clearer it is the more beautiful the scenery will be.
Mauna Loa's most recent eruption occurred in 1984. Having a closer look at the road's rough, patchy pavement, the thin white line down the middle of the pavement is a "fog line" to guide drivers when visibility is poor. Car and truck drivers need to straddle the fog line whenever possible, because the pavement is usually little more than one lane wide, and there isn't much shoulder between the pavement and fields of jagged lava; so treating the fog line as a lane divider, using only half the pavement, can be rather unkind to your passenger-side tires. 

Located within the Hawai‘i Volcanoes National Park, the journey offers superb views. It’s definitely worth it. A drive not to be missed! Don't forget your camera with lots of film/memory, fully charged batteries and an empty memory card! Driving through this excellent national park will provide breathtaking views, many pullouts where one can stop and get out and walk around, and loads of signage to help you decide where to go next. Only if the weather is clear and bright, should you consider a drive up Mauna Loa Road to its scenic lookout. On especially clear days there are spectacular views of Mauna Kea, Kohala, Haleakala (Maui), Hualalai, and the Pohakuloa saddle. Under optimum conditions some of the other islands from various points along this drive. Also be very careful around turns as the road is only slightly bigger than a car and you may not be the only person on the road.

Is Mauna Loa road safe?

The highest part of the road can be temporarily closed due to winter weather hazards.Do not attempt this drive in bad weather. If fog or clouds begin to set in leave immediately! This road is very dangerous in poor visibility and it is extremely easy to get lost or hurt on Mauna Loa.Be prepared for severe winter conditions, including blizzards, high winds, and whiteouts. Snow or driving rain are possible at any time of year. High altitude storms can occur without warning. Temperatures are below freezing at night all year round. Volcanic eruptions are possible at any time. Stay upslope from active lava flows and remain on high ground. Stay upwind of volcanic gasses.



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