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.