Mauna Kea Adz Quarry

Image of rock structure with hill in background. Photograph by Justin Shearer, Flickr
Rock shelter at Mauna Kea Adz Quarry.

Photograph by Justin Shearer, Flickr

Quick Facts
Mauna Kea Ice Age Natural Area Reserve, Hawaii
Primitive rock quarry
National Historic Landmark

Mauna Kea Adz Quarry, a large complex of archeological sites, is located on the south slope of the Mauna Kea volcano in the Mauna Kea Ice Age Natural Area Reserve on the Island of Hawai'i. The Adz Quarry is the largest primitive rock quarry in the world and was used by the ancient Hawaiians to both obtain basalt and make various stone tools.

An adze (adz) is an ancient type of edge tool dating back to the Stone Age. Similar to an axe in shape, it was used for cutting, smoothing, and carving wood and other materials. In the Hawaiian Islands, an adze blade was generally made out of basalt, a common volcanic rock formed by the rapid cooling of lava. Basalt was favored for tool making because of its hardness and ability to hold an edge. An adze was made by quarrying a suitable piece of rectangular basalt and then chipping at it with a piece of hard stone (hammerstone) until it took on the rough shape of an axe head. The upper and lower sides of the adze blade were then tapered using a grinding stone sprinkled with sand and water. Once the sides had been ground down and the edge was sharpened, the blade was secured to a wooden handle with a fiber cord. The finished adze was then ready to be used or traded for other goods or services.

The Hawaiian adze, referred to as a hafted adze, was attached to a bent wooden handle that allowed the user to swing it in a downward cutting motion. Occasionally a small adze blade would be fastened to the tip of a stick, and when the stick end was hit with a stone it would act as a chisel. The adze was one of the most important tools in the Hawaiian Islands and large adzes were used for cutting trees and shaping canoes while smaller ones were used to carve things such as furniture, bowls, weapons, idols, and small tools.

Basalt adze quarries were well known throughout the Hawaiian Islands. Because of the extremely high quality and large quantity of basalt on this part of Mauna Kea, the Mauna Kea Adz Quarry was the main area for adze production on the Island of Hawai'i. Radiocarbon dating indicates that the quarry was being used by 1000 A.D. with more intensive use after 1400 A.D. The area, which covers approximately seven and one half miles and is located between 8,600 feet and 13,000 feet in elevation, is made up of a series of surface and sub-surface quarries, workshop areas, religious shrines, and shelters. Most of the main sites can be found in a one to one and a half square mile area between 11,000 and 12,400 feet in elevation.

There is speculation that the Mauna Kea Adz Quarry was different from other adze–making sites in the Hawaiian Islands. It appears that the complex was used more like a modern manufacturing site with different areas being used for different aspects of adze making. Some areas contain pre-worked basalt "blanks" while others contain masses of small finishing flakes, adze preforms, and rejects. There was also a large amount of standardization in adze making in size, form, and procedure. This suggests that different people specialized in different aspects of adze manufacturing at the site and that the adze makers were specialists in their craft.
The closest permanent settlements to the Mauna Kea Adz Quarry were on the coast 25 miles away and there is no evidence of historic trails to the quarry site. It appears that travel to Mauna Kea was guided each year by individual knowledge of the landscape and the quarry's location. Because the site is located near the volcano summit (13,796 feet), it is believed that basalt quarrying and adze production took place during warmer months with no snow, generally July through October. The distance to the coast and the short work season meant that workers would have brought food and clothing with them and lived on site. Mauna Kea Adz Quarry has multiple shelters, primarily rock, overhang, and open-air walled. The rock shelters are small, natural enclosures suitable for habitation. They are generally stone-lined with fire hearths, stone walls at the entrances, and living areas. Overhang shelters are usually found near rock shelters and appear to have provided additional places to sleep. There are also open-air shelters with low, walled enclosures which are found primarily near workshop locations. The workshops (stone-chipping sites) vary in size; some have thin scatters of stone flakes, adze rejects, and hammer stones while others have large piles 20 to 30 yards across and up to three to four yards deep.

More than 35 shrines rest on high points throughout the complex. The shrines consist mostly of upright stones made of angular slabs of rock. The two classes of shrines at Mauna Kea Adz Quarry are occupational and non-occupational. Occupational shrines appear to be related to adze production, are generally found near workshops, and have items such as stone flakes and preformed blades left on or very near the shrines. Non-occupational shrines do not appear to be associated with adze making and range in complexity from small groups of upright stones to shrines with pavements, prepared courts, and a large number of uprights stones. It is thought that the shrines were meant for the different small and large gods associated with Mauna Kea. Non-workshop-associated shrines found near an open-air shelter at Lake Waiau, a sacred alpine lake near the summit, may possibly be associated with the snow line and Poli'ahu the goddesses of snow who resides on the volcano.

The Mauna Kea Adz Quarry was abandoned for unknown reasons prior to European contact. Today, visitors to the quarry area may see large debris piles, shelters, and shrines—all evidence of a once thriving Hawaiian adze–making complex.

Mauna Kea Adz Quarry, a National Historic Landmark, is located in the Mauna Kea Ice Age Natural Area Reserve on the southern slope of Mauna Kea on the Island of Hawai'i, HI. The Reserve may be accessed through the Mauna Kea State Recreation Area [Mauna Kea State Park] Halep'haku Area at the Mauna Kea Visitor Information Station on the Saddle Road (Highway 200), 35 miles west of downtown Hilo, HI. Car rental companies may prohibit or impose conditions for use of their vehicles on the Saddle Road and within the Reserve.

Mauna Kea Visitor Information Station is open from 9:00am to 10:00pm, 365 days a year. The Reserve and Mauna Kea summit are open daily and may be accessed via hiking trail or a steep graded-gravel road. Only true four-wheel drive vehicles with low range (LR) should be driven on the gravel road. The Mauna Kea Adze Quarry may be accessed from the Mauna Kea Humu'ula Trail. All visitors wishing to hike or drive in the Reserve or to the Quarry or summit must fill out a Visitor Information Sheet at the Mauna Kea Visitor Information Station. For more information, visit the Mauna Kea Visitor Information Station website. For daily weather and road conditions in the Reserve and at the summit call 808-935-6268.

Last updated: August 16, 2019