Kohala (mountain)

Kohala Mountain
Kohala volcano as seen from Mauna Kea
Elevation	5,480 ft (1,670 m) ^[1]
Pronunciation	[Hawaiian pronunciation: [koˈhɐlə]]
Location
Kohala Mountain Hawaii, USA
Range	Hawaiian Islands
Coordinates	^[1]
Topo map	USGS Kamuela
Geology
Type	Shield volcano, Hotspot volcano^[1]
Age of rock	Oldest dated rock:460,000 BP Estimated:1 million^[2]
Volcanic arc/belt	Hawaiian-Emperor seamount chain
Last eruption	About 120,000 years ago^[1]
Climbing
Easiest route	Kohala Mountain Road

Kohala is the oldest of five volcanoes that make up the island of Hawaii.^[3] Kohala is an estimated one million years old—so old that it experienced, and recorded, a reversal of magnetic field 780,000 years ago. It is believed to have breached sea level more than 500,000 years ago^[1] and to have last erupted 120,000 years ago. Kohala is 606 km² (234 sq mi) in area and 14,000 square kilometres (5,400 sq mi) in volume, and thus constitutes just under 6% of the island of Hawaii.^[1]

The volcano is cut by multiple deep gorges, the product of thousands of years of erosion. Unlike the typical symmetry of other Hawaiian volcanoes, Kohala is shaped like a foot. Toward the end of its shield-building stage 250,000 to 300,000 years ago, a landslide destroyed the northeast flank of the volcano, reducing its height by over 1,000 m (3,281 ft) and traveling 130 km (81 mi) across the sea floor. This huge landslide may be partially responsible for the volcano's foot-like shape.^[2] In 2004, marine fossils on the flank of the volcano were found, far too high to have been deposited by standard ocean waves. Analysis indicated that the fossils had been deposited by a massive tsunami approximately 120,000 years ago.

A dike complex near the volcano's main caldera plays a major role in Kohala's geomorphology. It separates runoff into two major drainage basins, the Waipiʻo and Waimanu valleys, and it maintains the volcano's shallow water table. Kohala supports a complex hydrological cycle that has been exploited to provide a water supply to island residents.

Because it is so far from the nearest major landmass, the ecosystem of Kohala has experienced the phenomenon of geographic isolation, resulting in an ecosystem radically different from that of other places. Invasive species introduced by man present a problem to Kohala's ecosystem, as they push native species out of their habitat. There are several initiatives to preserve Kohala's ecosystem. Crops, especially sweet potato (Ipomoea batatas), have been harvested on the leeward side of the volano for centuries as well. The northern part of the island is named after the mountain, with two districts named North and South Kohala. King Kamehameha I, the first King of the Kingdom of Hawaii, was born in North Kohala, near Hawi.

1 Geology
2 Ecology
3 Human history
4 References
5 Further reading

Geology

History

The location of Kohala relative to the other volcanoes

Studies of the volcano's lava accumulation rate have put the volcano's age at somewhere near one million years.^[2] It is believed to have breached sea level more than 500,000 years ago. Beginning 300,000 years ago, the rate of eruption slowly decreased over a long period of time to a point where erosion wore the volcano down faster than Kohala rebuilt itself through volcanic activity. Decreasing eruptions combined with increasing erosion caused Kohala to slowly weather away and subside into the ocean. The oldest lava flows that are still exposed at the surface are just under 0.78 million years old. It is difficult to determine the original size and shape of the volcano, as the southeast flank has been buried by volcanic lava flows from nearby Mauna Kea and Mauna Loa.^[1]^[4] However, based on a sharp increase of incline on the submarine slope of the volcano at a depth of 1,000 m (3,281 ft), scientists estimate that in its prime the portion of Kohala that was above the water was more than 50 km (31 mi) wide.^[1] Geologists estimate that the volcano was once about twice its current size.

The volcano is so old that it experienced, and recorded, a reversal of magnetic polarity (a change in the orientation of Earth's magnetic field so that the positions of the North and South poles interchange) that happened 780,000 years ago. Fifty different flow units in the top 140 m (459 ft) of exposed strata in the Pololu section are of normal polarity, indicating that they were deposited within the last 0.78 million years. Radiometric dating ranged mostly from 450,000 to 320,000 years ago, although several pieces strayed lower; this indicated a period of eruptive history at the time.^[2]

Cliffs as seen from the beach at Waipiʻo Valley

Kohala was devastated by a massive landslide between 250,000 and 300,000 years before present. Debris from the slide was found on the ocean floor up to 130 km (81 mi) away from the volcano. Twenty kilometers wide at the shoreline, the landslide cut back to the summit of the volcano, and is partially, if not largely, responsible for the volcano losing 1,000 m (3,281 ft) in height since then. The famous sea cliffs of the windward Kohala shoreline stand as evidence of the massive geologic disaster, and mark the topmost part of the debris from this ancient landslide.^[1] There are also several other unique features found on the volcano, all marks made by the decimating collapse.^[2]

Kohala is thought to have last erupted 120,000 years ago. However, several samples of a more recent date have been obtained. Two samples collected about 120 m (394 ft) apart, obtained from Waipiʻo Valley on the volcano's east flank in 1977, were dated reliably to 60,000 years. Another double set of samples, collected from the western part in 1996, was measured to be 80,000 years in age. The samples have been treated with skepticism by the scientific community, and their ages have been directly challenged. The rocks collected from the west site have not been tested by subsequent experiments. The lava collected from the eastern site were allegedly found under a Mauna Loa lava flow, which had been previously dated to 187,000 years. The general agreement is that the flows are 120,000 years at their youngest, conceivably younger.^[2]

In 2004, unidentified marine fossils were found at the base of the volcano 6 km (4 mi) inshore. A research team led by University of Hawaii's Gary McMurtry and Dave Tappin of the British Geological Survey in Nottingham found that the fossils had been deposited by a massive tsunami, 61 m (200 ft) above the current sea level.^[5] The team dated the fossils and nearby volcanic rock at about 120,000 years old. Based on the rate of Kohala's subsidence over the past 475,000 years, it was estimated that the fossils were deposited at a height of about 500 m (1,640 ft), well out of reach of storms and far above the normal sea level at the time.^[6] The timing corresponds with the last great landslide of nearby Mauna Loa. Researchers hypothesize that the underwater landslide from the nearby volcano triggered a gigantic tsunami, which swept up coral and other small marine organisms, depositing them on the western face of Kohala. Mauna Loa, an active volcano, has since repaired its flank. Dave Tappin, a marine geologist with the British Geological Survey believes that a "future collapse on this volcano, with the potential for mega-tsunami generation, is almost certain."^[6]

Structure

Kohala had two active rift zones, a characteristic common to Hawaiian volcanoes.^[2]^[7] The double ridge, shaped axially, was active in both the shield and postshield stages. The southeast rift zone passes under the nearby Mauna Kea and reappears further southeast in the Hilo Ridge, as indicated by the relationship between collected lava samples. In addition, the two features align to one another more closely then does the ridge to Mauna Kea, of which it was once thought to constitute a part. The bulk of the ridge is built of volcanic rock with reverse magnetic polarity, evidence that the volcano at least 780,000 years old. Older lava dated from the toe of the ridge was estimated to be roughly between 1.1 and 1.2 million years old.

The volcano's lava flows are sorted into two layers. The Hawi Volcanic layers were deposited in the shield stage of the volcano's life, and the younger Pololu Volcanics were deposited in the volcano's post-shield stage.^[2] The rock in the younger Hawi section, which overlies the older Pololu flows, is mostly 260 to 140 thousand years old, and composed mainly of hawaiite and trachyte. The separation between the two layers is not clear; the lowest layers may actually be in the Pololu section, based on their depositional patterns and low phosphorus content. The time intervals separating the two periods of volcanic evolution were extremely brief, something first noted in 1988.^[2]

The forest-covered summit of the volcano consists of many cones which generated lava from its two rift zones between 240,000 and 120,000 years ago.^[1] Kohala completed its shield-building stage 245,000 years ago and has been in decline ever since.^[8] Potassium-argon dating indicates that the volcano last erupted about 120,000 years ago in the late Pleistocene.^[1]^[9] Kohala is currently in transition between the shield and postshield Hawaiian volcanic stages in the life cycle of Hawaiian volcanoes.^[5]

The United States Geological Survey has assessed the extinct Kohala as a low-risk area. The volcano is in zone 9 (bottom risk), while the border of the volcano with Mauna Kea is zone 8 (second lowest), as Mauna Kea has not produced lava flows for 4,500 years.^[10]

Characteristics

Side view of Kohala. Deeply dissected valleys can be readily observed.

Kohala, like other shield volcanoes, has a shallow surface slope due to the low viscosity of the lava flows that formed it. Events during and after its eruptions give the volcano several unique geomorphic features, some possibly resulting from the ancient collapse and landslide. The volcano is shaped like a foot; the northeast coast extends prominently across 20 km (12 mi) of shoreline, differing from the ordinarily smooth, rounded shape of Hawaiian volcanoes.^[2]

There is a small string of faults on and near the main summit caldera, arranged parallel to the northern coast. The faults were originally regarded to be a direct result of the collapse; however scientists note the fault lines do not go all the way to the coast but are arranged tightly clustered around the caldera. This indicates that the fault lines may have been caused indirectly, possibly due to the sudden release of stress during the event.^[2]

Waipiʻo Valley, one of the most prominent valleys cutting into the volcano's flank

Kohala is dissected by multiple, deeply eroded stream valleys in a west-east alignment, cutting into the flanks of the volcano. Just north of Kohala's summit there is a small ridge that separates two streams by about a quarter of a mile. The ridge dictates whether the falling rain will go southeast, and plunge into Waipi'o Valley, or northwest, down into Honokane Valley. The ridge itself is part of the northwest-southeast trending rift zone. When the volcano was still active, vertical sheets of magma, arranged in what is known as dikes, forced their way out of the magma reservoir and intruded into the rift zone, which was weakened by the collapse.^[2]^[11] As the dikes forced their way up, they formed fractures and faults parallel to the rift zone. The exertion caused by the dikes produced a series of faults along the rift zone, forming horsts and grabens (fault blocks). In the northern region of Kohala, the faulted structure prevents rainwater from naturally flowing northeast down the mountain slope. Instead, the rainwater flows down laterally and empties directly into the ocean. Two grabens control the flow of water into the two valleys.^[11]

Landsat satellite composite of Kohala, showing its foot-like shape. The two deep gorges visible in this photo are Waipiʻo and Waimanu Valleys. In addition, one can see the effect of trade winds on valley development, as all of the gorges are on the east side.

The northwestern slope of Kohala has few stream valleys cut into it, the result of the rain shadow effect—the dominant trade winds bring most of the rainfall to the northeastern slope of the volcano.

The valleys are more than 800 m (2,625 ft) in depth, among the oldest and largest of which are the Waipiʻo and Waimanu valleys.^[12] The volcano stayed active well into the formation of these mountainside valleys, as illustrated by later Pololu lava flows, which separated into two directions and often flowed into Pololu Valley. Recent seafloor mapping seems to show that the valley extends a short way into the seafloor, and it is believed the valley formed from the tumbled-out rock from the landslide.^[2]

In addition to being the primary factor behind the faulting structure, the dike complex plays another important role in the development of the enormous valleys—that of creating and maintaining the water table. Hawaiian lava is extremely permeable and porous. Rainwater easily seeps into the lava, creating a large lens of fresh water below the island surface. In most places, the top of the water table is just a few feet from sea level. Unlike porous lava flows, however, dikes cool underground into dense rock with few cracks and vesicles. The dikes act as impermeable walls through which groundwater cannot flow. Rainwater that would ordinarily seep right through the ground gets trapped in the dike "reservoirs," located well above sea level. The groundwater is confined to a flow along the dike until it finds a means to escape. In Kohala, the numerous dikes near the summit inhibit groundwater from seeping downslope to the northeast, where it naturally wants to go. Rather, the Kohala dike complex guides it northwest or southeast, down the axis of the rift zones, before the water can escape. Therefore, most of North Kohala's groundwater ends up in either the Waipi'o/Waimanu drainage or in the Honokane/Pololu drainage. The enormous amount of water routed through these areas results in a large amount of water erosion, which causes the valley walls to frequently collapse, accelerating valley development.^[11]

On the other hand, the numerous smaller, shallow shallow stream valleys between the large ones, such as Honokane Iki, 'Awini, Honopue, Waikapu, 'Apua, and Laupahoehoe, are deprived of groundwater by the orientation of the rift zone and its dikes. Without the large amount of water that is received by the bigger valleys, these valleys grow far more slowly. Meanwhile, the fault graben structure staves off stream flow near the summit, and the main caldera is affected relatively little by erosion from water.^[11]

Ecology

Flower of Opuntia species in South Kohala.

The natural habitats in the Kohala district range across a wide rainfall gradient in a very short distance—from less than 5 in (127 mm) a year on the coast near Kawaihae, to more than 150 in (3,810 mm) a year near the summit of Kohala Mountain, a distance of just 11 mi (18 km). At the coast are remnants of dry forests, and near the summit lies a cloud forest, a type of rainforest that obtains much of its moisture from "cloud drip" in addition to precipitation.^[13] These large cloud forests dominate its slopes. This biome is rare, and contains a disproportionate percentage of the world's rare and endemic species.^[14] The soil at Kohala is nitrogen-rich, facilitating root growth.^[15]

The happy combination of small trees, bushes, ferns, vines, and other forms of ground cover keep the soil porous and allow the water to percolate more easily into underground channels. The foliage of the trees breaks the force of rain and prevents the impact of soil by raindrops. A considerable portion of the precipitation is let down to the ground slowly by this three-story cover of trees, bushes, and floor plants and in this manner the rain, falling on a well-forested area, is held back and instead of rushing down to the sea rapidly in the form of destructive floods, is fed gradually to the springs and to the underground artesian basins where it is held for use over a much longer interval...^[16]

C S Judd, Superintendent of Forestry in Hawaiʻi, 1924

The forest lies perpendicular to the prevailing trade winds, a characteristic that leads to frequent cloud formation and abundant rainfall. Thus the rain forests carpeting Kohala are vital to the supply of groundwater on the island. The role of Kohala's ecosystem in supporting water flow has long been recognized. As early as 1902, US Forester E M Griffith wrote "Forest protection means not only increasing the rainfall, but more important still, conserving the water supply. The future welfare and agricultural prosperity of the Hawaiian Islands depends upon the preservation of the forest."^[16]

Prior to the arrival of humans, the wildlife population at Kohala and on the rest of the island was isolated from other species, as it was separated from the nearest major landmass by over 2,000 mi (3,219 km) of open water. The early colonizers of Kohala came by wind, storm or floating on the ocean. Successful colonizations occur on the magnitude of once every 35,000 years. The 2,000 successful ancestors that arrived at Kohala evolved into about 8,500 to 12,500 unique species, resulting in a very high ratio of the species present being found nowhere else on Earth. Only about 2.5% of the world's rainforest is cloud rainforest, making it a unique habitat as well.^[16]

A specimen of ʻŌhai (Sesbania tomentosa), a native species of Hawaii that is endangered and suffering from the introduction of invasive species.

The mountain supports approximately 155 native species of vertebrates, crustaceans, mollusks, and plants. A diverse complexion of fungi, liverwort, and mosses further add to the variety. In fact, up to a quarter of the plants in the forest are mosses and ferns. These work to capture the water from clouds, in turn providing microhabitats for invertebrates and amphibians, and their predators. Estimates on the water capacity of the forest range from 792 US gal (2,998 l) to 3,962 US gal (14,998 l) per hectare.^[16]

The mountain is also home to several bogs, which exist as breaks in the cloud forests. It is believed that bogs form in low lying areas where clay in the soil prevents proper water drainage, resulting in an accumulation of water that impedes the root systems of woody plants. Kohala's bogs are characterized by sedges, mosses of the genus Sphagnum, and the endangered ʻŌhai (Sesbania tomentosa). Other habitats include rain forest and mesophytic (wet) forests.^[16]

The same isolation that produced Kohala's unique ecosystem also makes it very vulnerable to invasive species. Alien plants and feral animals are among the greatest threats to the local ecology. Plants like the kahili ginger (Hedychium gardnerianum) and the strawberry guava (Psidium littorale) displace native species.^[14] Prior to human settlement, many major organisms such as conifers and rodents never made it onto the island, so the ecosystem never developed defenses against them, leaving Hawaii vulnerable to damage by hoofed animals, rodents, and predation.^[16]

Kohala's native Hawaiian rain forest has a thick layer of ferns and mosses carpeting the floor, which act as sponges, absorbing water from rain and not letting much of it through to the soil; when feral animals like pigs trample the covering, the forest loses its ability to hold in water effectively, and the result is a severe loss of topsoil, much of which ends up being dumped by streams into the ocean.^[14]

Human history

Sweet potato (Ipomoea batatas) of the type grown on Kohala.

There is evidence of pre-modern agriculture on the leeward slopes of Kohala. From 1400 to 1800, the principal crop grown at Kohala was sweet potato (Ipomoea batatas), although there is also evidence of yams (Dioscorea sp.), taro (Colocasia esculenta), bananas (Musa hybrids), sugarcane (Saacharum officinarum), and gourds of the family Cucurbitaceae. The optimal rainfall level for the sweet potato lies between 30 to 50 inches (76–130 cm) per year. A combination of factors makes the rainfall at Kohala variable both from location to location and from year to year. In addition, Kohala is buffeted by strong winds, which are directly correlated to soil erosion; ancient farmers utilized a series of earthen embarkments and stone walls to protect their crops. This technique has been shown to reduce wind by at least 20–30 percent.^[17]

In addition to walls, there are a series of stone paths that divided the farmed area into plots of variable size. These structures are unique because although many people used such systems at the time, Kohala has some of the few to survive.^[17] The leeward slopes of Kohala were used for sugar plantations in the late 19th century. The trip from the fields to the mills and then boats was mechanized by steam locomotive in 1883.^[18] Several plantations on the mountain were consolidated into the Kohala Sugar Company by 1937.^[18] At the peak of its production, the company had 600 employees, 13,000 acres (20 sq mi) of land, and a capacity of 45,000 t (99,208,018 lb) of raw sugar per year. In 1975 the company finally closed down.^[19]

Kohala supports a very complex hydrological cycle. In the early part of the 20th century, this was exploited by building surface irrigational channels designed to capture water at the higher elevations and distribute it to the then-extensive sugarcane industry. In 1905, after 18 months and the loss of 17 lives, the Kohala Ditch, a vast network of flumes and ditches, measuring 22 mi (35 km) in length, was completed.^[19] Its has since come into use by ranches, farms, and homes.^[16] A portion of the ditch became a tourist attraction until it was damaged by the 2006 Hawaii earthquake, centered just southwest of the mountain.^[20]

The Hawaii County Department of Water Supply relies on streams from Kohala to supply water to the population of the island. With increasing demand, the original surface channels have been supplemented by deep wells designed to channel groundwater for domestic use.^[16]

In 2003 the Kohala Watershed Partnership (KWP) was formed, a voluntary group of private land owners and state managers, designed to help manage the Kohala watershed and to protect it from threats, most especially invasive species.^[14]

The northern Kohala district, centered on the town of Hawi

Another project to raise awareness of Kohala's ecosystem is the The Kohala Center, an independent, not-for-profit, community-based organization for research and education. It was established as a response to requests by island residents to create an educational and employment opportunity related to Hawaii's natural and cultural significance. The center's mission is "to respectfully engage the Island of Hawaiʻi as an extraordinary and vibrant research and learning laboratory for humanity."^[21]

The land around Kohala is administered as two districts, North Kohala and South Kohala, of the County of Hawaiʻi. The beaches, parks, golf courses, and resorts in South Kohala are called "the Kohala Coast."^[22]^[23]

King Kamehameha I, the first King of the unified Hawaiian Islands, was born near Upolu Point, the northern tip of Kohala. The site is within Kohala Historical Sites State Monument. The original Kamehameha Statue stands in front of the community center in Kapaʻau, and replicas of the statue are found at Aliʻiōlani Hale in Honolulu, and in the United States Capitol at the Hall of Columns in Washington, D.C.^[24]

References

↑ ^1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 ^1.10 "Kohala - Hawai`i's Oldest Volcano". Hawaiian Volcano Observatory. United States Geological Survey. 1998-03-20. http://hvo.wr.usgs.gov/volcanoes/kohala/. Retrieved 2008-08-22.
↑ ^2.00 ^2.01 ^2.02 ^2.03 ^2.04 ^2.05 ^2.06 ^2.07 ^2.08 ^2.09 ^2.10 ^2.11 ^2.12 "Geological Map of the State of Hawaii". USGS Hawaii geology pamphlet. USGS. 2007. http://pubs.usgs.gov/of/2007/1089/Hawaii_expl_pamphlet.pdf. Retrieved 2009-04-12. pp. 41–43
↑ Another, Māhukona, has since sunk below sea level. Loihi, the youngest and smallest volcano in the chain, has neither risen from sea level nor connected with the island. Neither are usually included in the five.
↑ "Kohala Volcano, Hawaii-Photo Information". USGS Image. USGS. http://hvo.wr.usgs.gov/volcanoes/kohala/2553085_caption.html. Retrieved 2009-03-30.
↑ ^5.0 ^5.1 Seach, John. "Kohala Volcano - John Seach". Volcanism reference base. John Seach, volcanologist. http://www.volcanolive.com/kohala.html. Retrieved 2009-03-30.
↑ ^6.0 ^6.1 "Hawaiian tsunami left a gift at foot of volcano". New Scientist (Reed Business Information) (2464): 14. 2004-09-11. http://www.newscientist.com/article/mg18324641.900-hawaiian-tsunami-left-a-gift-at-foot-of-volcano.html. Retrieved 2008-12-18.
↑ Garcia, Michael O.; Jackie Caplan-Auerbanch, Eric H. De Carlo, M.D. Kurz, N. Becker (2005-09-20) (PDF). Geology, geochemistry and earthquake history of Lōʻihi Seamount, Hawaiʻi. This is the author's personal version of a paper that was published on 2006-05-16 as "Geochemistry, and Earthquake History of Lōʻihi Seamount, Hawaiʻi's youngest volcano", in Chemie der Erde - Geochemistry (66) 2:81-108. SOEST. http://darchive.mblwhoilibrary.org:8080/dspace/handle/1912/1102. Retrieved 2009-03-20.
↑ Moore, James G.; David A. Clague (1992-11). "Volcano growth and evolution of the island of Hawaii". GSA Bulletin (Geological Society of America) 104 (11): 1471–1484. doi:10.1130/0016-7606(1992)104<1471:VGAEOT>2.3.CO;2. http://bulletin.geoscienceworld.org/cgi/content/abstract/104/11/1471. Retrieved 2008-12-18.
↑ McDougall, Ian (December 1969). "Potassium-argon ages on lavas of Kohala volcano, Hawaii". GSA Bulletin (Geological Society of America) 80 (12): 2597–2600. doi:10.1130/0016-7606(1969)80[2597:PAOLOK]2.0.CO;2.
↑ "Lava Flow Hazand Zone Maps:Mauna Kea and Kohala". USGS. http://pubs.usgs.gov/gip/hazards/maunakea-kohala.html. Retrieved 2009-03-30.
↑ ^11.0 ^11.1 ^11.2 ^11.3 "Origin of the Big Island's Great Valleys Revealed in Hawaiian chant". USGS weekly feature. USGS. 2006-02-16. http://hvo.wr.usgs.gov/volcanowatch/2006/06_02_16.html. Retrieved 2009-04-12.
↑ Mouginis-Mark, Pete. "Airphotos of Kohala". Photos of Kohala. Virtually Hawaii group, Hawaii Center of Volcanology. http://satftp.soest.hawaii.edu/space/hawaii/nav/ap.kohala.html. Retrieved 2009-03-30.
↑ Gon III, S.M.. "Hawaiian High Islands Ecoregion". The Nature Conservancy. http://www.hawaiiecoregionplan.info/CAHA.html. Retrieved 2009-05-13.
↑ ^14.0 ^14.1 ^14.2 ^14.3 "Working together to protect and sustain the forest, the water, and the people of Kohala Mountain". Hawaii Association of Watershed Partnerships. 2008. http://hawp.org/kohala.asp. Retrieved 15 December 2009.
↑ Riley, Ralph H; Ralph H. Riley, Peter M. Vitousek (1995). "Nutrient Dynamics and Nitrogen Trace Gas Flux During Ecosystem Development in Montane Rain Forest". Ecology (Ecological Society of America) 76 (1): 292–304. doi:10.2307/1940650. ISSN 0012-9658. http://www.esajournals.org/doi/abs/10.2307/1940650. Retrieved 2009-12-15.
↑ ^16.0 ^16.1 ^16.2 ^16.3 ^16.4 ^16.5 ^16.6 ^16.7 "Kohala Mountain Watershed Managment Plan DRAFT". Kohala Watershed Partnership. December 2007. pp. 9, 18–19, 25–28. http://www.state.hi.us/dlnr/dofaw/wpp/KWP_MgmtPlan_Dec07.mkp.2.pdf. Retrieved 16 December 2009.
↑ ^17.0 ^17.1 "Archeological Evidence for agricultural development in Kohala, Island of Hawaiʻi". Journal of Archeological Science (Elsevier B. V.) 30 (7): 923–940. July 2003. http://www.sjsu.edu/faculty/mdmccoy/Ladefoged_et_al_2003.pdf. Retrieved 2009-12-18.
↑ ^18.0 ^18.1 S. Schweitzer, Veronica (2006). "Sugar and Steam in Kohala". Coffee Times. http://www.coffeetimes.com/jan98.htm. Retrieved 25 December 2009.
↑ ^19.0 ^19.1 S. Schweitzer, Veronica (2006). "Kohala Ditch". Coffee Times. http://www.coffeetimes.com/ditch.htm. Retrieved 25 December 2009.
↑ "Flumin' da Ditch". web site. http://www.flumindaditch.com/. Retrieved 2009-12-25.
↑ "The Kohala Center". The Kohala Center. 2008. http://www.kohalacenter.org/. Retrieved 16 December 2009.
↑ "Kohala Coast vacation on the Big Island of Hawaii". www.kohalacoastweb.com. 2009. http://www.kohalacoastweb.com/index.html. Retrieved 2009-11-07.
↑ Sperling, Kandra (2009). "Island of Hawaii Golf Courses". MerchantCircle. http://www.merchantcircle.com/directory/HI-Kapaau/pluckit?PLUCKarticleId=4bc0d1e5-02a7-c45d-a669-2aa29964fe15&PLUCKtitle=Island_of_Hawaii_Golf_Courses&PLUCKmediaType=Text&PLUCKauthor=Kandra%20Sperling&PLUCKapiKey=28624137-1421-4b6d-a75c-28ae3993b2a8&PLUCKwhichPage=articlePage. Retrieved 2009-11-07.
↑ Pawlak, Debra. "The Lonely One:The Story of King Kamehameha the Great". The Mediadrome. http://www.themediadrome.com/content/articles/history_articles/kamehameha.htm. Retrieved 2009-03-30.