This backpacking trail has a total elevation difference of 6,527 feet which is a higher than average number. There is only one trailhead, so in and out is the way to backcountry walk it normally. Of course, this is an overnight hike, 4 days normally, so it's a fine thing if your backpack is big enough to do the job. Mauna Loa Trail is 26.8 miles long; it's a long wilderness trail. Different parts of this wilderness trail are at very different elevations which of course means you need to be prepared for different conditions on different parts of the wilderness trail. Keep in mind that this is a long hiking trail, so don't forget to pack enough supplies.