HALEAKALA, Maui — A fence to keep out animals that could damage the rainforest at Haleakala National Park on Maui has been completed after seven years of work.

The fence, which surrounds 12,000 acres of forest and rare plant life, is an attempt to keep destructive feral goats, pigs and axis deer out of the fragile forest.

The goat population has been mostly eliminated from the area inside the fence, but pigs occasionally find their way through, said Ron Nagata, a member of the executive committee of the East Maui Watershed Partnership.

Deer are more difficult to keep out, but Nagata said he hopes the fence serves as a deterrent.

These animals are dangerous to the rainforest because they forage on bark and seedlings while devouring just about anything that's green.

The partnership to protect the rainforest started adding nine miles of fence in 1999.

Three miles had been finished by 2002, and additional money from the Fish and Wildlife Service and the Department of Land and Natural Resources helped hasten construction. Private contributors include East Maui Irrigation, Haleakala Ranch, Hana Ranch Partners and The Nature Conservancy.

The barrier helps protect the Waikamoi preserve, an important source of drinking water. All the enclosed areas serve as a catchment for rain that waters central Maui fields and provides drinking water.

It would take an 8-foot-high fence to keep deer from jumping over the fence, and the partnership didn't want to build it that high because they feared it would snare the rare dark-rumped petrels, a variety of seabirds that nest near the crater rim, Nagata said.

Even then, deer could still get through by charging at the fence until it breaks, he said.

"If you have a herd of 15 or 20 wanting to go through," they will, said Nagata, who is also chief of resources at the park.

The fence will be patrolled for breaks caused by falling trees or animals.

Previously, goats had learned to climb koa trees and used them as springboards to jump over the fence. Park officials put a stop to that by trimming the tree branches, Nagata said.