Southwest of Hilo in the Hawaii Volcanoes National Park on the Big Island, the Mauna Loa Trail, a 36 mile route up 6,600 feet to the 13,677 summit from rainforest to snowcap. This is typically a 3 day hike with a moderate grade and ocean vistas. The route runs through volcanic landscape with jagged lava fields and big lava tubes. There are two types of lava along the way: Pahoehoe lava with a firm and solid footing, and A a lava which has variable and unpredictable footing.
The trail begins at the end of Mauna Loa Road (about 7.5 miles up from Saddle Road), and there is a mid-camp at Red Hill Cabin (Puu Ulaula Rest House) at 10,035 (first-come, first-serve).
Be prepared for rain, snow, severe cold, wind and intense sun.
Overall, Mauna Loa Trail is the 3rd most popular hiking trail of all 45 hikes in Hawaii.