Tip: The first quarter mile of the road was left unpaved and is full of potholes, but the remainder is smooth.
At the long curved top of Mauna Loa are the assemblage of weather stations and astrophysical monitoring devices that keep a watch on global climate change, among other events.
The paved road to these structures is now gated, but you can arrange for a tour by calling 808-933-6965. Parking at the top is also for the trail that leads to the peak: 6 miles, one way, with a gain of 2,500 feet. Not bad, but altitude is an issue, since you begin at over 11,000 feet. The mountain's slopes, created by zillions of tons of lava piling up are not steep, averaging about a 12 percent grade. This big dome effect makes Mauna Loa easily the world's most massive peak, with 100 times more cubic feet than Mainland volcanoes like Rainier and St. Helen's (even before it blew its cork). Complete driving directions can be found to Mauna Loa and Mauna Kea peaks in your Hawaii Big Island Trailblazer guide.