Hawai'i's last large intact rain forest, a 25,856-acre forest in Puna valued by Native Hawaiians for its ecological and cultural significance, soon could be in the possession of the state Office of Hawaiian Affairs and protected from development.

The Board of Land and Natural Resources on Friday authorized Land Board director Peter Young to enter into an agreement paving the way to transfer to OHA several parcels known collectively as Wao Kele o Puna.

Cost of the purchase from Campbell Estate is estimated to be about $3.65 million.

The purchase would mark the end of a decades-old dispute involving Campbell, the state and Native Hawaiian groups, a dispute that led to protests and arrests in the late 1980s, when the rain forest was being eyed for development of geothermal energy. The tract is about three miles southeast of Pahoa High School on the Big Island.

The Trust for Public Land, a national nonprofit organization dedicated to protection of key conservation lands, helped the DLNR secure $3.4 million in congressional funding for the purchase through the Forest Legacy Program. The remaining $250,000 was approved by the OHA board of trustees.

Palikapu Dedman, president of the Pele Defense Fund, said the impending purchase culminates a nearly 20-year effort by his group to ensure that Native Hawaiians will be allowed to continue using the rain forest to practice their religious and cultural customs.

"I'm just glad that the state recognized that they have responsibilities and they ruled in our favor on native gathering rights," Dedman said in a phone conversation from his home in Puna. "And I'm also happy that OHA stepped up to the responsibility of securing those rights. It was a long struggle."

OHA administrator Clyde Namu'o, who was on the Mainland on Friday, acknowledged that trustees had agreed to the purchase but neither he nor trustees would comment until a news conference scheduled for this afternoon.

Theresia McMurdo, a spokeswoman for Campbell, confirmed that the estate has a tentative agreement with the Trust For Public Lands for purchase of the property.

An OHA staff report described the site as "the last large intact unprotected native lowland forest ecosystem in the state of Hawai'i."

Also according to the report: "The property is comprised of a combination of dense native 'ohi'a forest and areas of recent lava flow where kipuka (islands of vegetation in the flow) serve as seed banks for future generations of forests."

In 1996, a state Circuit Court issued a landmark ruling — in favor of the Pele Defense Fund and against Campbell — that said Native Hawaiians can establish traditional rights of access to private property for traditional hunting, plant-gathering and subsistence purposes.

The property has been sitting idle since 1994, when Wyoming-based True Geothermal Co. announced that it was ending its troubled quest to harness the heat under Wao Kele generated by Kilauea Crater as geothermal energy to be used to meet the electrical needs of the state.

Development of geothermal energy in Puna was slowed in the late 1980s by a series of protests led by Native Hawaiian organizations and Puna residents fearful of health concerns and other impacts. Some of the protests involved hundreds of people and resulted in dozens of arrests.

While True's plans never were realized, Puna Geothermal Venture continues today as the sole operator of a geo-thermal plant on the Big Island.

Wells drilled at Wao Kele are expected to be plugged. According to a DLNR staff report, the DLNR and OHA will share management responsibilities initially but OHA would eventually have sole responsibility. OHA intends to transfer the site to a federally recognized Hawaiian entity at some point.

Campbell Estate, set up as a trust under the will of James Campbell, must terminate by Jan. 20, 2007, and its assets must be distributed to beneficiaries. It put the Wao Kele lands, its second-largest piece of real estate, up for sale in 2001.

According to an OHA staff report, the parcels were once government and crown lands that were ceded to the United States at annexation and transferred to the state at statehood to be held as a forest reserve.

In 1981, one of the parcels, about 16,800 acres, was designated by the state as the Wao Kele O Puna Natural Area Reserve as part of a mandate to "preserve in perpetuity specific land and water areas which support communities, as relatively unmodified as possible, of the natural flora and fauna, as well as geological sites, of Hawai'i."

But in 1987, the BLNR transferred the property to Campbell in a land exchange in the hope that geothermal energy could be developed that would help reduce the state's dependence on foreign oil.

While wells were drilled on the property, according to the OHA staff report, "subsequently ... attempts at exploration and drilling proved unprofitable."

Reach Gordon Y.K. Pang at gpang@honoluluadvertiser.com.