A lot can change in five decades. But after 100 years, the USDA Forest Service is betting the Allegheny National Forest will still be here.

The Forest Service is inviting the public to contribute small, flat items, three-by-five inches or smaller for a time capsule to commemorate the ANF’s centennial.

Suggested items include photographs, postcards, stickers, letters, sketches and poems, according to a Forest Service news release.

The items will be placed in a time capsule to be opened at a public ceremony in September of 2073 – 50 years from now.

Those wishing to contribute can bring items to the ANF Centennial Celebration at Twin Lakes Recreation Area.

The event is scheduled from 11 a.m. until 7 p.m. on Sunday, Sept. 24. It will also feature food trucks, beverage vendors, history displays, kids’ activities speakers, live music, an official ceremony at 1:30 p.m. and a centennial tree planting.