Excerpts
In spite of the fear and aversion the ancient Hawaiians had of Mauna Kea's summit, they discovered an area containing a fine-grained, dense rock, proved invaluable for the making of adze blades. The site was used from around 1,000 AD.

The quarry spans seven and a half square miles at an elevation ranging from between 11,000 to 12,400 feet. It is believed to be the most important quarry site exploited in Hawaii. Anthropologist Patrick McCoy of the Bishop Museum writes: "The Mauna Kea Adze Quarry is probably one of the nation's least known but most important National Historic landmarks, from both a research and interpretive point of view. It is the only landmark of its kind in the United States....it is probably one of the largest and most complex stone tool quarries in the world."

The adze...was the Hawaiian's most important tool. It was used for nearly every aspect of building and carving....It was a fundamental tool used throughout the Pacific and was, in fact, one of the earliest stone tools used by man thousands of years ago.

A specialized guild of adze craftsmen (poe kakoi) quarried and shaped the rock. These men were probably few in number.

McCoy and Richard Gould...noted "any prehistoric expedition to the adze quarry must have involved a carefully planned visit of at least two or more weeks during the relatively short summer." Even those summer nights, though, were frigid. Warm clothing, bedding and food had to be transported along with other items such as kukui nuts (the oil from them was burned for light) and water containers.

The area was barren of all but rock for miles. Lake Waiau, small and thick with algae, provided a source of fresh water. Getting to it, however, involved a strenuous two-mile hike uphill, along a rugged footpath. The adze makers were able to shelter themselves in a few small, natural caves and alcoves. The most tedious job of flaking the pieces of rock to their pre-form shapes appears to have been done in front of these shelters, which provided close refuge from the harsh elements.

Prior to shaping the pre-forms, or adze blanks, the adze maker identified and quarried the rock. Some of the resulting pits are fifteen feet deep. Extracting the rock was accomplished with the aid of levers or by simply hammering rock against rock. Chosen stones were then reduced to a near final size and tested for flaws before the secondary shaping began.

These men did not rely entirely on their own skills. Heiaus were erected to appease the gods and invoke their assistance. Forty of these shrines were built over the years the site was in use. Some, with their uprighted stones still standing, top the most prominent rock outcroppings and are scattered throughout the quarry.

Judging by the large number of rejected adze blanks strewn over voluminous piles of flake tailings, the craftsmen had a high standard of excellence. They were, no doubt, reluctant to descend the mountainside with any that were questionable. Some pre-forms weighed as much as fifteen pounds each. When the adze makers returned to their permanent dwellings, the pre-forms were ground and polished to their final form. They then had valuable items for bartering.

Stone adzes were used even after the introduction of metal. In the hands of the skilled user, they may have exceeded some functions of the metal ones. Ellis reported, "Though they now use an axe in felling trees, the adze is still their favorite tool and many of them use no other."

And William T. Bingham, director of the Bishop Museum in 1901, wrote of his firsthand experience, "In watching the shaping of a canoe I have seen the old canoe maker use for the rough shaping and excavating an ordinary foreign steel adze, but for the finishing touches he dropped the foreign tool and returned to the adze of his ancestors, and the blunt looking stone cut off a delicate shaving from the very hard koa wood."

To the adze maker, the dense basaltic rock of the quarry was recognized as a valuable source of material in the manufacture of vital tools. Geologists, however, recognized the exposed core rock as evidence of a glacier that stripped an ancient lava flow of its loose crust.