Haleakala National Park covers the summit area of the larger of the two volcanic mountains that make up Maui. The National Park’s boundary has fingers that extend down the Hana side of the mountain, all the way to the ocean. (The entire park includes the Kipahulu area, where Ohe’o Gulch (Seven Pools) and Pipiwai Trail are found – this article includes only the Summit Area.)
Geologically Speaking
Speaking of “crater” this is a good time to explain that the summit area is actually not a typical crater formed by volcanic activity (such as you would see on the Big Island of Hawai’i.) Haleakala Crater is so gigantic because it was formed over eons as the result of erosion of the entire volcanic mountain top. Over this period of time, smaller lava flows back-filled the eroding valley, building up the floor of what is commonly called the Haleakala Crater. The cinder cones that dot the landscape here are the last of these most recent eruptions (and these individually have true volcanic craters.)
Read the full article here.