Kaupo Gap is a deep and rugged valley with the only lowlands on the section of coast between Kipahulu and Ulupalakua. The village of Kaupo is around the 35-mile marker and is mostly not in evidence. Basically, this is a community of paniolos, many of them third-generation Kaupo Ranch hands.

Kaupo Ranch is one of the largest private land holdings in East Maui and is located about two miles up the slope from the Kaupo Store. Citrus was cultivated on the hillsides in the early 1900s but the venture failed, mostly because it was hard to get the fruit to market from the isolated district. Cattle ranching is the main economic activity these days.

Kaupo used to be a heavily settled area. Numerous fishing villages were scattered throughout the area. The district has 30 recorded heiau. Loaloa Heiau is the largest, a very ancient heiau said to have been built by the menehune, and it was one of the first sites in East Maui to be registered as a National Historic Landmark.

In 1730, Maui's King Kekaulike built Popoiwi heiau, a pu'uhonua (place of refuge) in Kaupo. This refuge sits close to Huialoha Church, a restored Congregational church which was built in 1859 near the shoreline just east of Kaupo Gap, on the rocky black-sand Mokulau Beach. The area was an ancient surfing site and is named "many small islands" for the rocks offshore. The church was restored in 1978.

Numerous churches, many of them mere shells, dot the landscape, marking the locations where the settlements once existed. Some of the churches used abandoned Hawaiian heiau as foundations.

In earlier times, the Hawaiians gathered salt from the depressions in the boulders at Nuu Bay. More than 50 ancient Hawaiian petroglyphs have been recorded in the area. The bay was also a landing, where the cattle were taken by ship to market in Honolulu. In 1997, Nuu Pond, a small pond that sits behind the cobble beach at Nuu Bay, was fenced in to keep cattle out of the area. Sightings of native birds, including the Hawaiian stilts and coots increased.

The scenery is stark and rugged. Most of it is cattle country. Past the Kaupo Store the road is unpaved and rutted for three miles.

Between Kaupo and Keokea, there are traces of a very large village called Kahikinui, which is now in ruins. The Dept. of Hawaiian Home Lands has 22,000 acres in the area, making it one of the major land owners in Kahikinui. Homestead development in the area for native Hawaiians is in progress through a new kuleana program that allows homesteaders to occupy the land and build before extensive infrastructure is in place.

Through Kahikinui, the road generally follows the old Hoapili Highway, an upland trail built in the 19th century. The road continues west through wide open dry areas with patches of native wiliwili trees and other introduced species. The majority of the plants in this area are thorny and tough. They are the only plants that can survive the arid conditions and the depredations of the cattle and the large wild goat herds. The road has a panoramic view of the rolling hillsides and open cattle range above La Perouse Bay.

It is said that "in the old days," you could walk from Kahikinui to Makawao and never once leave the shade of the trees. This was probably before the lava flows in the late 1700s cut a wide swath through the dry land forests of the district, and before the days of the sandalwood trade, when the chiefs ordered their people up into the mountains to harvest the iliahi, sandalwood, for which there was a great demand in China. The chiefs kept their people in the mountains so much that the work the people needed to do to feed their own families was disrupted, and the people retaliated by uprooting the new sprouting trees so the forest died more quickly.

This was also before the free-ranging wild cattle released in the hills in the 1790s caused extensive damage to plant life, denuding the mountain side and changing the wind and rain patterns.

At one time, there was a sizeable Hawaiian population in Ulupalakua and Kahikinui, supported by extensive cultivation of dry land taro and sweet potato, supplemented by coastal fishing. Now it is mostly an arid land below the cloud belt. The cattle are still there.