All-ages coloring books have never been more popular, and now you can help actually create one that is themed around the National Parks.

Collaborative website HitRecord is working on a coloring book project that’s part of a broader series of efforts celebrating the 100th anniversary of the National Park Service next year. The book is set to be filled with images associated with the parks—from iconic landmarks and historical figures to animals—and they’re asking for photographers and illustrators to get involved. Photographers can upload a snapshot from one of the United States' National Parks, while illustrators can “remix” the photos into coloring book pages using a template on the site.

In a video on the collaboration page, you can get more details about how to get involved and join the 881 people (at the time of writing) who have already lent their hand. The deadline for submissions is October 25, so put on your centennial celebration hat and get to work. Or, you can just browse the many photos and templates already up—it's a great way to appreciate the NPS from your office chair.