HALEAKALA NATIONAL PARK, Hawaii » The National Park Service plans to remove 3,000 invasive pine trees at Haleakala National Park with the help of helicopters.

The operation begins Monday and will last through Thursday. It will be rescheduled for the middle of next month if the weather is bad.

The park service says helicopters are needed because the trees are growing on terrain that is too remote or too steep to safely reach on foot.

The invasive trees are Monterey pine, Mexican weeping pine and maritime pine. They’re displacing endemic and endangered species as they spread through Haleakala’s crater.

The park service plans to station employees at overlooks to answer the public’s questions when the helicopters are operating.

A second phase of the tree removal project will be carried out next summer.