Haleakala National Park will celebrate National Public Lands Day by waiving entrance fees this weekend.

The park also is seeking volunteers to protect native ecosystems by removing invasive weeds and trash on Saturday. Volunteers will meet at the summit parking lot at 9:30 a.m. Warm clothes, long pants and closed boots are required; lunch at Hosmer Grove will follow.

To sign up, call the Pacific Whale Foundation at 249-8811.

Volunteers seeking a more rugged experience can sign up for a two-night wilderness service trip to Kapalaoa Cabin in the crater from Saturday through Monday. Sign up by calling the Friends of Haleakala National Park at 248-7660.