These two sections, the coastal and the mountain summit area, together draw 1,450,000 visitors annually. The summit-area depression, misnamed Haleakalā Crater, formed as erosion ate away the mountain, joining two valleys. This 19-square-mile wilderness area, 2,720 feet deep, is the park's major draw. The crater measures nearly seven miles across, two miles wide, and 2600 feet deep.
The road to the summit of Haleakalā rises from near sea level to 10,023 feet in 38 miles—possibly the steepest such gradient for autos in the world. Visitors ascend through several climate and vegetation zones, from humid subtropical lowlands to subalpine desert. Striking plants and animals such as the Haleakalā silversword and the nēnē may be seen in this mountain section.
Because it is on a volcanic area, all of the plants and animals that are now present on the island were brought by pioneers or arrived here naturally after a lengthy two thousand mile journey through the air or sea. Once the organisms got here, they underwent strange adaptations to make the species unique. More endangered species live in Haleakalā National Park than any other national park in the United States.
I was in Hawai'i in 2003 with an Elderhostel adventure group for two weeks and we hiked in Haleakala one day, but I wish we could have spent more time here, hiked down to the bottom of the crater, and biked downhill on the road as we saw others doing. I also would have driven the three-plus hours to the other unit of the park, the Kapahulu District, to experience the coastal section of the park.
The Wilderness Area of Haleakalā National Park was designated on October 20, 1976 with 19,270 acres. This protected Wilderness expanded to 24,719 acres in 2005.
You pass through as many ecological zones on a two hour drive to the summit of Haleakalā as you would on a journey from Mexico to Canada. The Civilian Conservation Corps (CCC) built many of the trails and structures in Haleakalā National Park in the mid-1930s.
The scenery is spectacular and otherworldly. The only other strikingly otherworldly location I have been to would be some of Yellowstone's thermal areas.
Wast of the rim, the great rain forest valley of Kīpahulu drops thousands of feet down to the coast. The upper Kīpahulu Valley is a biological reserve with no public access, which is home to a vast profusion of flora and fauna, including some of the world's rarest birds, plants, and invertebrates. Some insects and plants evolved in the Kīpahulu Valley and live nowhere else.
Visitors reach the lower valley of Kīpahulu via the long winding Ha-na Highway. Dominated by intense hues—azure sea, black rock, silver waterfalls, green forest and meadow—the coastal area was first farmed in early Polynesian times, more than 1,200 years ago. Mark Twain, who traveled to Hawai'i in 1866, may well have had this part of Kīpahulu in mind when he wrote: "For me its balmy airs are always blowing, its summer seas flashing in the sun; the pulsing of its surfbeat is in my ear; I can see its garlanded crags, its leaping cascades, its plumy palms drowsing by the shore." (info from National Geographic.)