On the upper slopes of Haleakalā, this remote and heavily forested park is the place for solitary forest hiking. Check the park website or call before you make the drive (4WD only) or hike in. Trails and facilities can be closed due to weather damage, with downed trees and flash floods affecting the trails. There's a cabin and camping facilities, but the park sits at 6200ft, so it can get chilly at night. Bring wet-weather gear.